Stay cautious even after vaccination against COVID-19
Dr. Roach writes: In a previous column, I deferred making a recommendation about a COVID-19 vaccine until more data were available. The Food and Drug Administration has now made the safety and efficacy data publicly available for the Pfizer COVID-19 vaccine. It has been approved and already given in the U.K, and is approved for use in the U.S., with doses being distributed as I write this. After thoroughly reviewing the data, I recommend getting the vaccine when it becomes available to you. I plan to get it as soon as it is offered, as the benefits far outweigh the risks, in my opinion.
Over 20,000 study participants received the vaccine; another 20,000+ received a placebo. The FDA reported data up to four months after subjects received their first vaccination. Eight cases of confirmed COVID-19 occurred in the group that got the vaccine, compared with 162 in the group that received placebo, meaning the vaccine is 95% effective.
The age of the subject had little effect, with a 96% effectiveness in those ages 16-55, and 94% in those 55 and older. The vaccine started to become effective at 14 days. People with a history of COVID-19 infection benefitted from the vaccine just as much as those without, suggesting no natural immunity was present.
Vaccine reactions were common and expected. The most common unsolicited patients reports included redness or swelling at the injection site (11%), fatigue (6%), headache (5%), muscle pain (5%) and fever (5%). Serious adverse events were rare, less than 0.5%. This puts the vaccine at somewhat more likely to cause a mild side effect than a typical flu vaccine, but less likely than the shingles vaccine.
Some people have worried that the vaccine has been rushed. Indeed, this is the fastest a vaccine has ever been approved, but knowledge on vaccine development has dramatically improved in the past few years. What is most important is the large number of people who volunteered to be in the studies. Some people are also worried that because the vaccine is an MRNA virus, it could change a person’s DNA. That isn’t possible.
There are some important unknowns. The most important is that we do not know how long immunity to the vaccine will last. It may be that people will need booster shots. Further, there are immense challenges to getting a large enough proportion of the population vaccinated so that ongoing transmission will be disrupted. The virus is so entrenched in the population now that it will be a massive undertaking.
If we think of COVID-19 as the enemy, the vaccine is an important weapon in the war. However, a single weapon doesn’t win the war. There simply won’t be enough vaccine available as fast as we would like, so it remains as important as ever to take all the steps we can to prevent further infections. That especially means social distancing, hand hygiene and mask-wearing. Most important of all is to avoid large gatherings, especially indoors.