Can first Covid-19 vaccines bring herd immunity? Experts have doubts

Governments and officials are voicing hopes that Covid-19 vaccines could bring “herd immunity”, with some calculating that immunising just two-thirds of a population could halt the pandemic disease and help protect whole communities or nations.

But the concept comes with caveats and big demands of what vaccines might be capable of preventing. Some experts say such expectations are misplaced.

For a start, figuring out what’s needed to achieve herd immunity with Covid-19 vaccines involves a range of factors, several of which are unknown.

What is the rate of the spread of the Covid-19-causing virus? Will the first vaccines deployed be able to stop transmission of the virus, or just stop people getting ill? How many people in a population will accept a vaccine? Will vaccines offer the same protection to everyone?

“Herd immunity is sometimes wrongly understood as individual protection,” said Josep Jansa, an expert in health emergency preparedness and response at the Stockholm-based European Centre for Disease Prevention and Control (ECDC).

“It’s inappropriate to think ‘I will not be affected myself because there is herd immunity’. Herd immunity refers to community protection, not to how an individual is protected.”

The ECDC uses an estimated herd immunity threshold of 67 per cent for its models, while Chancellor Angela Merkel said this month that Covid-19 restrictions in Germany could be lifted if 60pc to 70pc of the population acquired immunity, either via a Covid-19 vaccine or through infection.

World Health Organisation experts have also pointed to a 65-70pc vaccine coverage rate as a way to reach population immunity through vaccination.

“The idea of herd community is to protect the vulnerable,” said Eleanor Riley, a professor of immunology and infectious disease at the University of Edinburgh. “And the idea behind it is that if, say, 98pc of a population have all been vaccinated, there will be so little virus in the community that the 2pc will be protected. That’s the point of it.”

Reproduction rate is crucial

Central to the public health calculations on this concept for Covid-19 is the reproduction rate, or R value, of the virus that causes it. This is a measure of how many other people an average infected person passes a pathogen on to in “normal”, or restriction-free, circumstances.

Assuming complete vaccine efficacy, herd immunity percentage thresholds for infectious diseases are calculated by dividing 1 by the R value, deducting the result from 1, and multiplying by 100.

For instance, herd immunity from highly contagious measles, with an estimated R value of 12 or higher, will kick in only if 92pc or more within a group are immune. For a seasonal flu strain that could have an R value of 1.3, the threshold would be just 23pc.

“The problem is that for now we don’t know exactly how fast the virus spreads without any precautions and with the normal travel and social activities we had a year ago,” said Winfried Pickl, professor of immunology at the Medical University of Vienna.

With so many countries still operating in far from normal circumstances, the assumption should be that the Covid-19 R value would be “closer to 4 than to 2”, he said, since even with semi- or full lockdown measures the R value is around 1.5.

Additionally, anything less than 100pc vaccine efficacy — such as the 90pc or so suggested in early data on the Pfizer-BioNTech and Moderna Covid-19 shots — would require a matching rise in percentage of coverage to reach herd threshold.

Amesh Adalja, a scholar at the Johns Hopkins Center for Health Security, said a good target for immunity in the United States would be for more than 70pc of the population to be inoculated, but added that the figure could go up if vaccines are less effective.

Stop transmission in the ‘herd’?

Experts say another important factor is whether the Covid-19 vaccines a government chooses to deploy can stop transmission of the virus.

Evidence so far suggests the first Covid-19 vaccines to come to market will at least stop people developing the disease. But it cannot be ruled out that people will still catch the Sars-CoV-2 virus and pass it on to others unnoticed.

“While protection against illness has a value for an individual, it will not prevent circulation of virus and risk of disease in unvaccinated (people),” said Penny Ward, a visiting professor in pharmaceutical medicine at King’s College London.

Bodo Plachter, a professor and deputy director of the Institute of Virology at Germany’s Mainz University teaching hospital, said that respiratory infections in particular can be hard to block completely with vaccines — although the shots will go some way to reducing the amount of circulating virus.

“It may well be that vaccinated people will shed fewer viruses,” he said. “But it would be a mistake to assume vaccination alone can suppress a pandemic.”

Focus on protecting the vulnerable?

Edinburgh’s Riley said this suggests that for now, pursuing an idea of herd immunity through Covid-19 vaccination is fruitless.

A better approach, she said, could be to “turn herd immunity on its head”, and use the first limited supplies of vaccines to protect those most in need, without worrying about the more robust members of the “herd” who can live relatively happily with the virus.

“Let’s forget about protecting the masses to protect the vulnerable,” she said. “Let’s directly protect the vulnerable.”

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How Much Water Should You Drink Per Day?

Your body is about 60 percent water.

The body constantly loses water throughout the day, mostly through urine and sweat but also from regular body functions like breathing. To prevent dehydration, you need to get plenty of water from drink and food every day.

There are many different opinions on just how much water you should be drinking every day.

Health experts commonly recommend eight 8-ounce glasses, which equals about 2 liters, or half a gallon a day. This is called the 8×8 rule and is very easy to remember.

However, some experts believe that you need to sip on water constantly throughout the day, even when you’re not thirsty.

As with most things, this depends on the individual. Many factors (both internal and external) ultimately affect how much water you need.

This article takes a look at some water intake studies to separate fact from fiction and explains how to easily stay well hydrated for your individual needs.

How much water do you need?

How much water you need depends on a lot of things and varies from person to person. For adults, the general recommendation from The U.S. National Academies of Sciences, Engineering, and Medicine is about:

• 11.5 cups (2.7 liters) a day for women
• 15.5 cups (3.7 liters) a day for men

This includes fluids from water, beverages like teas and juice, and from food. You get an average of 20 percent of your water from the foods you eat (1, 2).

You might need more water than someone else. How much water you need also depends on:

• Where you live. You will need more water in hot, humid, or dry areas. You’ll also need more water if you live in the mountains or at a high altitude (3Trusted Source).
• Your diet. If you drink a lot of coffee and other caffeinated beverages you might lose more water through extra urination. You will likely also need to drink more water if your diet is high in salty, spicy, or sugary foods. Or, more water is necessary if you don’t eat a lot of hydrating foods that are high in water like fresh or cooked fruits and vegetables.
• The temperature or season. You may need more water in warmer months than cooler ones due to perspiration.
• Your environment. If you spend more time outdoors in the sun or hot temperatures or in a heated room, you might feel thirstier faster.
• How active you are. If you are active during the day or walk or stand a lot, you’ll need more water than someone who’s sitting at a desk. If you exercise or do any intense activity, you will need to drink more to cover water loss.
• Your health. If you have an infection or a fever, or if you lose fluids through vomiting or diarrhea, you will need to drink more water. If you have a health condition like diabetes you will also need more water. Some medications like diuretics can also make you lose water.
• Pregnant or breastfeeding. If you’re pregnant or nursing your baby, you’ll need to drink extra water to stay hydrated. Your body is doing the work for two (or more), after all.

SUMMARY

Many factors affect how much water you need to stay healthy such as your health, activity, and environment.

Does water intake affect energy levels and brain function?

Many people claim that if you don’t stay hydrated throughout the day, your energy levels and brain function start to suffer.

There are plenty of studies to support this.

One study in women showed that a fluid loss of 1.36 percent after exercise impaired mood and concentration and increased the frequency of headaches (4Trusted Source).

Another study in China that followed 12 men in university found that not drinking water for 36 hours had noticeable effects on fatigue, attention and focus, reaction speed, and short-term memory (5).

Even mild dehydration can reduce physical performance. A clinical study on older, healthy men reported that just a 1 percent loss of body water reduced their muscle strength, power, and endurance (6).

Losing 1 percent of body weight might not seem like a lot, but it’s a significant amount of water to lose. This usually happens when you’re sweating a lot or in a very warm room and not drinking enough water.

SUMMARY

Mild dehydration caused by exercise or heat can have negative effects on both your physical and mental performance.

Does drinking a lot of water help you lose weight?

There are many claims that drinking more water may reduce body weight by increasing your metabolism and curbing appetite.

According to a study, drinking more water than usual correlated to a decrease in body weight and body composition scores. (7Trusted Source).

Another review of studies found that chronic dehydration was associated with obesity, diabetes, cancer, and cardiovascular disease (8Trusted Source).

Researchers in another older study estimated that drinking 68 ounces (2 liters) in one day increased energy expenditure by about 23 calories per day due to a thermogenic response, or a faster metabolism (9Trusted Source). The amount was incremental but could add up over time.

Drinking water about a half hour before meals can also reduce the number of calories you end up consuming (10Trusted Source). This might happen because it’s easy for the body to mistake thirst for hunger.

One study showed that people who drank 17 ounces (500 mL) of water before each meal lost 44% more weight over 12 weeks, compared to those who didn’t (11Trusted Source).

Overall, it seems that drinking adequate amounts of water, particularly before meals, may give you a boost in managing appetite and maintaining a healthy body weight, especially when combined with a healthy eating plan.

What’s more, drinking plenty of water has a number of other health benefits.

SUMMARY

Drinking water can cause slight, temporary increases in metabolism, and drinking it about a half hour before each meal can help you eat fewer calories.

Both of these effects can contribute to weight loss in some people.

Does more water help prevent health problems?

Drinking enough water is required for your body to function in general. Several health problems may also respond well to increased water intake:

• Constipation. Increasing water intake can help with constipation, a very common problem (12, 13).
• Urinary tract infections. Recent studies have shown that increasing water consumption may help prevent recurring urinary tract and bladder infections (14Trusted Source, 15)
• Kidney stones. An older study concluded that high fluid intake decreased the risk of kidney stones, though more research is needed (16Trusted Source).
• Skin hydration. Studies show that more water leads to better skin hydration, though more research is needed on improved clarity and effects on acne (17Trusted Source, 18)

SUMMARY

Drinking more water and staying adequately hydrated may help with some health problems, such as constipation, urinary and bladder infections, kidney stones, and skin dehydration.

Do other fluids count toward your total?

Plain water is not the only drink that contributes to your fluid balance. Other drinks and foods can have a significant effect.

One myth is that caffeinated drinks, such as coffee or tea, don’t help you hydrate because caffeine is a diuretic.

In fact, studies show that the diuretic effect of these beverages is weak, but they can cause extra urination in some people (19Trusted Source). However, even caffeinated drinks help add water to your body overall.

Most foods contain water in varying levels. Meat, fish, eggs, and especially fruits and vegetables all contain water.

Together, coffee or tea and water-rich foods can help maintain your fluid balance.

SUMMARY

Other beverages can contribute to fluid balance, including coffee and tea. Most foods also contain water.

Indicators of hydration

Maintaining water balance is essential for your survival.

For this reason, your body has a sophisticated system for controlling when and how much you drink. When your total water content goes below a certain level, thirst kicks in.

This is carefully balanced by mechanisms similar to breathing — you don’t need to consciously think about it.

Your body knows how to balance its water levels and when to signal you to drink more.

While thirst may be a reliable indicator of dehydration, relying on feeling thirsty may not be adequate for optimal health or exercise performance (20Trusted Source).

At the time thirst strikes, you may be already feeling the effects of too little hydration such as fatigue or headaches.

Using your urine color as your guide can be more helpful to know if you’re drinking enough (21). Aim for pale, clear urine.

There really is no science behind the 8×8 rule. It is completely arbitrary (1, 22Trusted Source). That said, certain circumstances may call for increased water intake.

The most important one may be during times of increased sweating. This includes exercise and hot weather, especially in a dry climate.

If you’re sweating a lot, make sure to replenish the lost fluid with water. Athletes doing long, intense exercises may also need to replenish electrolytes, like sodium and other minerals, along with water.

Your water need increases during pregnancy and breastfeeding.

You also need more water when you have a fever and when you’re vomiting or have diarrhea. If you desire to lose weight, consider upping your water intake too.

Furthermore, older people may need to consciously watch their water intake because the thirst mechanisms can start to malfunction with aging. Studies show that adults over 65 years old are at a higher risk for dehydration (23).

SUMMARY

Most people don’t need to focus too much on their water intake, as the body has an automatic thirst signal.

However, certain circumstances do call for increased attention to how much water you’re drinking.

The bottom line

At the end of the day, no one can tell you exactly how much water you need. This depends on many factors.

Try experimenting to see what works best for you. Some people may function better with more water than usual, while for others it only results in more frequent trips to the bathroom.

If you want to keep things simple, these guidelines should apply to the majority of people:

1. Drink often enough throughout the day for clear, pale urine.
2. When you’re thirsty, drink.
3. During high heat and exercise and other mentioned indications, make sure to drink enough to compensate for the lost or extra needed fluids.
4. That’s it!

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Pfizer and BioNTech: Our coronavirus vaccine is 90% effective

A coronavirus vaccine developed by the American company Pfizer and the German company BioNTech is 90% effective in preventing COVID-19 infections, the companies say.

According to preliminary results, patients were protected from the disease seven days after the second of two doses was given and 28 days after the first.

“The first results from our phase 3 tests of the COVID-19 vaccine provide early indications that the vaccine is capable of preventing COVID-19,” Pfizer CEO Albert Bourla said in a statement.

“We are one big step closer to being able to give people around the world a much-needed breakthrough to end this global health crisis,” the statement further stated.

However, the results do not mean that a vaccine is imminent. 

Preliminary results

The preliminary results are based only on 94 cases of infections that have so far been registered among 44,000 people in the USA and other countries.

The news comes as the coronavirus is on the rise in large parts of the world, with more and more people being admitted to intensive care units. 

The company says it expects to be able to offer around 50 million doses of the vaccine in 2020 and up to 1.3 billion doses in 2021.

The vaccine is among ten candidates who are in the final stages of testing.

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Shifa Foundation Organized Awareness Ceremony On Breast Cancer

The Shifa Foundation organized the closing ceremony of Breast Cancer Awareness Month at GIGA Mall, Islamabad to raise awareness of the disease that’s why it is now projected in every country almost. Throughout October, Shifa Foundation conducted various breast cancer awareness campaigns; with an aim to provide awareness on how to avert and treat breast cancer, before it gets very late.

The closing ceremony of the campaign Pink Lady Goes Virtual Against Breast Cancer was with a moto to provide awareness to maximum people and let them know that breast cancer is a fatal disease and not any taboo so women should come forward and talk about it. Free 50 percent discount mammography coupons were also given to the interested people.

People showed prodigious participation towards the breast cancer awareness; they got registered, donated for the noble cause openhandedly, supported the pink lady campaign on social media and spun the wheel to win exciting prizes.
Shifa Foundation is highly obliged to Shifa International Hospital for making the closing campaign a huge success. 

We are as well thankful to Sanso, Revive, Prime water, Shezan, Primo, Jacked Nutrition and Opulence, Bake Bees, The Royal Cakery, Folk Studio, Ali Broast, Explorica and Dastaan Art We hope to get more people donating us so we can help more breast cancer patients to live longer.

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Pakistan’s daily Covid-19 cases cross 1,000 mark for first time since July

ISLAMABAD – Pakistan reported more than 1,000 cases of Covid-19 for the first time since July on October 29, it emerged on Friday.

In a statement, the National Command and Operation Centre (NCOC) said 1,078 people tested positive for the virus on Thursday while 20 others died of the respiratory illness.

According to data collected by Dawn.com, Pakistan last reported more than a thousand cases on July 29 when 1,074 infections were recorded.

In a press release issued today, the NCOC said Pakistan currently has 11,864 active cases while 32,933 tests were conducted on Thursday.

Of these, 11,504 were carried out in Sindh, 11,432 in Punjab, 3,211 in Khyber Pakhtunkhwa, 5,229 in Islamabad, 603 in Balochistan, 355 in Gilgit-Baltistan and 599 in Azad Jammu and Kashmir.

“So far 313,527 people have recovered across the country making it a significant count,” the statement said. It added that out of 1,884 ventilators allocated for Covid-19 patients, 98 were currently occupied. “There is no patient on a ventilator in GB and Balochistan,” it said.

There are 753 hospitals with Covid-19 facilities with 808 patients admitted across the country, the statement said.

Pakistan has witnessed an uptick in the Covid-19 positivity ratio in recent days. A day earlier, Minister for Planning, Development and Special Initiatives Asad Umar said the national positivity rate had exceeded three per cent after more than 70 days.

Punjab Health Minister Dr Yasmin Rashid also urged the nation to wear face masks and practice social distancing to curb the spread of the virus. “If standard operating procedures [SOPs] are not followed, I’m afraid we will have to resort to stricter measures,” she warned.

Earlier this week, the NCOC announ­ced a schedule for commercial and social activities in 11 cities most vulnerable to the virus. These cities include Karachi, Lahore, Islamabad, Rawalpindi, Multan, Hyderabad, Gilgit, Muzaffarabad, Mirpur, Peshawar and Quetta.

Commercial activities — markets, shopping malls, marriage halls and restaurants — will be closed at 10pm and amusement/public parks at 6pm daily. Wearing a mask has been made mandatory at public places while a fine of Rs6,000 to Rs35,000 and a punishment of six-month imprisonment will be slapped on violators.

Meanwhile, Special Assistant to the Prime Minister (SAPM) on Health Dr Faisal Sultan formally announced on Tuesday that the second wave of the virus has started in the country. Dr Sultan said the public was not following SOPs to the extent necessary for curbing the spread of the virus.

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