There is more information on Pfizer BioNTech and Moderna vaccines than Johnson & Johnson vaccines, simply because trials of the former start earlier than the latter, explains Timothy Brewer, MD, professor of medicine and epidemiology at UCLA. And the available data is promising. Recently, Pfizer announced that its vaccine efficacy remained at 91% for test participants six months after the second dose. “It’s really encouraging news,” said Dr. Brewer. “And it doesn’t mean the effectiveness of the vaccine won’t last any longer, it just means that’s all the data we have so far.”
Moderna also has the data—It comes from a much smaller sample – that shows the vaccine’s long-term effectiveness. According to Dr. Brewer, 33 Moderna test participants maintained binding antibodies and neutralizing antibodies for up to 209 days after their second dose. “That is preliminary evidence of the effectiveness of both Pfizer and Moderna lasting six months and possibly longer,” he said.
It is important for you to understand that when you get one of these vaccines, the effectiveness does not go away one day for a night. Instead, what you will experience is a slow decline over time. But the injections cause your body to produce antibodies – and oh my memory, helping your body remember the infection and respond more effectively to it in the future – at levels that are actually much higher than you might need to fight the virus. So as they decrease, you are not protected, you are only less protected than the very high rate that you were initially protected. “That means you have a very long time left before the levels drop far enough to really stay within the range that you could be re-infected or seriously ill if infected,” says Dr. Brewer.
And there is some evidence that six months is likely, as Dr. Brewer noted, to be a conservative estimate of efficacy. A small one learn showed that spontaneous people infected with COVID-19 maintained antibodies for eight months later, and since the vaccine produces more antibodies than the natural infection, it is likely that you will be protected longer after vaccinations.
However, the duration of protection depends on some degree of virus mutation. “Protection is a function of two parts. So one part is how good and durable the immune response is, and the second part is how much the virus changes, ”says Dr. Brewer. “One of the reasons you get a flu shot every year is not because your immunity to that particular flu virus has weakened. Instead, since the flu virus has changed enough, over time, when you come into contact next year it is a slightly different virus. “
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Fortunately, the coronavirus doesn’t change or mutate at a rate similar to that of the flu virus, says Dr. Brewer. And if we get vaccinated fast enough, we will be able to slow or even stop the mutations of SARS-CoV-2, the virus that causes COVID-19. “In order for the SARS CoV-2 virus to change to produce what we call variants, you need to have replication and transmission,” he said. “So if there is no duplication and no transmission, there will be no creation of new variations.”
Worrying Variations already existhowever, there is some confusion and concern as to whether the current vaccines protect against them.
According to Dr. Brewer, the data we have so far suggests that the three vaccines currently available in the US provide “very good” protection against variant B.1.1.7, native to the UK. The other two related variants had additional mutations that could make them easier to evade; however, Pfizer tested the vaccination on 800 people in South Africa, many of whom were exposed to variant B.1.351, and none of them caught COVID-19. Johnson & Johnson also tested their vaccines in South Africa and Brazil, where variant P.1, and shows one hundred percent effective in preventing fatal illness and death, even when exposed to more dangerous variants. So when you hear that our current vaccines are less effective for these variants, Dr. Brewer says it’s important to remember again that you’re under moderate protection. is bigger than you need, so lower protection is still protection and maybe even possible good protection.
The best thing about new vaccine technology is that it is essentially plug-and-play, meaning vaccines can be changed quite easily to include new mutations as they arise. Pharmaceutical companies have been working on boosters specially designed to provide better protection against more disturbing variants, although it’s not yet known when or whether those will be made public.
Overall, there is still much to learn before we know for certain how long the COVID-19 vaccine will last, Dr. Brewer said. But the thing to do now is that you are well protected from all variations for at least six months – and possibly longer. “We still have to be careful, but relaxing a little is reasonable advice – vaccines are great and they work really well, ”he said. “Everyone should definitely get vaccinated, still take precautions, but you don’t have to worry about staying up all night.”