Representatives from Public Health England and AstraZeneca did not respond to requests for comment.
The Pfizer and AstraZeneca vaccines introduce a protein called pico into the body that, while not infectious, can teach immune cells to recognize and fight the real coronavirus.
Vaccines for covid19>
Answers to your vaccine questions
With the distribution of a coronavirus vaccine starting in the United States, here are the answers to some questions you may be asking yourself:
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- If I live in the USA, when can I get the vaccine? Although the exact order of vaccine recipients may vary by state, most will likely put doctors and residents of long-term care facilities first. If you want to understand how this decision is being made, this article will help you.
- When can I return to normal life after being vaccinated? Life will only return to normal when society as a whole obtains sufficient protection against the coronavirus. Once countries authorize a vaccine, they will only be able to vaccinate a few percent of their citizens, at most, within the first two months. The unvaccinated majority will still remain vulnerable to infection. An increasing number of coronavirus vaccines are showing robust protection against disease. But it is also possible for people to spread the virus without even knowing they are infected, because they have only mild symptoms or none at all. Scientists still do not know whether vaccines also block coronavirus transmission. So for now, even vaccinated people will need to wear masks, avoid crowds indoors and so on. Once enough people are vaccinated, it will be very difficult for the coronavirus to find vulnerable people to infect. Depending on the speed with which we as a society achieve this goal, life may begin to approach something normal in the fall of 2021.
- If I have already been vaccinated, do I still need to wear a mask? Yes, but not forever. Here’s why. Coronavirus vaccines are injected deep into the muscles and stimulate the immune system to produce antibodies. This appears to be sufficient protection to prevent the vaccinated person from becoming ill. But what is unclear is whether the virus can flourish in the nose – and be sneezed or expired to infect others – even if antibodies elsewhere in the body have been mobilized to prevent the vaccinee from getting sick. The vaccine’s clinical trials were designed to determine whether vaccinated people are protected from disease – not to find out whether they can still spread the coronavirus. Based on studies of flu vaccines and even patients infected with Covid-19, the researchers have reason to hope that vaccinated people will not spread the virus, but more research is needed. In the meantime, everyone – even vaccinated people – will need to think of themselves as possible silent spreaders and continue to wear a mask. Read more here.
- It will hurt? What are the side effects? The Pfizer and BioNTech vaccine is given as an injection into the arm, like other typical vaccines. The injection in your arm will be no different than any other vaccine, but the rate of short-term side effects appears to be higher than that of a flu vaccine. Tens of thousands of people have already received the vaccines and none have reported serious health problems. Side effects, which may resemble Covid-19 symptoms, last for about a day and are more likely to appear after the second dose. Initial vaccine test reports suggest that some people may need to take a day off from work because they feel bad after receiving the second dose. In the Pfizer study, about half developed fatigue. Other side effects occurred in at least 25 to 33 percent of patients, sometimes more, including headaches, chills and muscle pain. While these experiences are not pleasant, they are a good sign that your own immune system is building a potent response to the vaccine that will provide lasting immunity.
- Will mRNA vaccines change my genes? No. The Moderna and Pfizer vaccines use a genetic molecule to prepare the immune system. This molecule, known as mRNA, is eventually destroyed by the body. The mRNA is packaged in an oily bubble that can fuse with a cell, allowing the molecule to slide inward. The cell uses mRNA to make proteins from the coronavirus, which can stimulate the immune system. At any given time, each of our cells can contain hundreds of thousands of mRNA molecules, which they produce to make their own proteins. As soon as these proteins are produced, our cells fragment the mRNA with special enzymes. The mRNA molecules that our cells make can survive just a matter of minutes. The mRNA in vaccines is designed to resist the cell’s enzymes a little more, so that cells can produce extra proteins from the virus and stimulate a stronger immune response. But mRNA can only last a few days at most, before being destroyed.
But vaccines transmit their immunological lessons through different methods and do not contain equivalent ingredients. While the Pfizer vaccine depends on a molecule called messenger RNA, or mRNA, packaged in fatty bubbles, AstraZeneca vaccines are designed around a virus shell that delivers DNA, a cousin of mRNA.
Both vaccines should be distributed in two-dose regimens, administered three or four weeks apart. Although the first injections of each vaccine are considered somewhat effective in preventing Covid-19, it is the second dose – intended to be a kind of molecular review session for the immune system – that closes the protective process.
Although it is possible that exchanging one vaccine for another could still teach the body to recognize the coronavirus, it is still a scientific bet. With different ingredients in each vaccine, people may not benefit as much from a second injection. Mixing and matching can also make it difficult to collect clear data on the safety of the vaccine.
Without evidence to support it, the hybrid vaccination approach looks “premature,” said Saad Omer, a vaccine expert at Yale University. Still, it is not without precedent: health officials like the CDC previously said that if it is impossible to administer doses of a vaccine from the same manufacturer, “providers must administer the vaccine they have available” to complete an injection schedule.
In a controversial move, the British government also decided this week to anticipate the launch of its vaccine, delivering as many first doses as possible to people – a move that could delay the second injection by up to 12 weeks.
Rapid deployment can offer partial protection to more people from the virus in the short term. But some experts, including Dr. Moore, fear that this, too, could be unwise and could put vulnerable populations at risk.