Adults 50 years and older who have previously received three mRNA doses may receive a second booster dose if at least four months have elapsed since their first. Anyone who received two doses of the Johnson & Johnson vaccine can also receive an additional dose of mRNA four months after their last booster.
Many people are wondering: Does this mean everyone will need an annual Covid-19 refresher? Do we need more frequent booster shots? Is it combined with the flu shot? Are new vaccines being developed targeting new variants? And should they wait to get the booster if they’re eligible, or get it now?
dr Leana Wen: We do not know yet. There are many variables here, and only time – and ongoing research – will tell.
First, we do not know how long the immune protection from vaccination and the first booster lasts. There are many indications that the first booster is very important. At a time when Omicron was the dominant variant, the effectiveness of three doses against serious illnesses remained high at 94%, according to a study by the US Centers for Disease Control and Prevention. If this protection drops significantly, it would be a sign that another booster is needed.
Second, new variants may develop over time. The influenza vaccine is given annually, having been reconfigured for new mutations each year. The current vaccines work well against the Omicron subvariants, but if there are future variants that evade vaccine-induced immunity, this is another reason for additional vaccinations.
Third, we need to monitor how widespread Covid-19 is. At the moment it’s still widely available around the world, but if it ends up fading then regular booster doses may not be necessary. like dr Anthony Fauci, President Joe Biden’s chief medical adviser, told CNN, “Will it eventually get to such a low level that we might not even need a boost every year?” It’s possible, but we don’t know yet.
Fourth, we need to assess whether future Covid-19 outbreaks are clearly seasonal. Other coronaviruses that cause colds are more common in winter, as are other respiratory viruses such as RSV (respiratory syncytial virus) and influenza. It’s likely SARS-CoV-2 is, too, and there has been a spike over the winter months. However, this part is yet to be seen in the coming fall and winter seasons.
Finally, logistical considerations must be made. Adding an annual vaccine is a big undertaking. Uptake of the influenza vaccine is already low; only about half of Americans get it each year. Given the misinformation and polarization surrounding Covid-19, promoting this level of frequency will be a major undertaking.
CNN: Right now, a second booster is allowed as little as four months after the first, which means the current frequency is more than once a year. Could boosters be needed even more than once a year?
Whom: It is possible. I want to emphasize that there is a lot we don’t know simply because we don’t have the ability to predict the future.
There are a few different scenarios that could occur. One is that certain groups of people may need more frequent vaccinations. Recall that people who are moderately or severely immunocompromised have been advised to take their supplemental boost for months. It is possible that, in the future, certain more vulnerable populations will be recommended to be vaccinated more frequently than the general population.
In addition, there must also be contingencies if a new variant emerges that evades a previous immunity. It should be possible to develop, manufacture and quickly distribute variant-specific vaccines. In this case, the frequency could be more than once per year for a certain period of time.
In the future, we must also consider the availability of other therapies and mitigation measures. For example, Evusheld is an antibody infusion that, when given to people who are immunocompromised, is very effective in reducing the likelihood of progression to a serious disease. Antiviral pills and monoclonal antibodies are effective treatments when given early in the course of the disease. And there are other preventive measures, including masks and pre-meeting testing, that can also reduce the risk.
CNN: If the The Covid-19 vaccination is given annually, would it make sense to combine it with the flu vaccination?
Whom: Theoretically yes, but we just don’t know if the Covid-19 vaccine needs to be an annual vaccination.
There are other vaccines that last longer. For example, the Tdap (tetanus-diphtheria vaccine) requires a booster shot every 10 years. The polio vaccine is a four-dose vaccine—you get four doses and you’re done. Hepatitis B is a three-dose vaccine.
It’s possible that Covid-19 could be three or four doses and we’re done, or it may need to be updated more frequently, like with the flu. Again, we just don’t know yet. If it’s something annual and the seasonal pattern is similar to the flu, then a combined shot—or at least at the same time as the flu shot—would make sense.
CNN: Why aren’t there any variant-specific vaccines that target Omicron?
Whom: Scientists are now working on these vaccines. They are testing Omicron-specific vaccines and boosters to see if they could be even more effective than the original vaccines, which targeted previously dominant variants.
One consideration is that additional variants may emerge, and scientists need to consider whether the Omicron-specific vaccines or the original vaccine – or a combination – will most likely be effective against potential variants in the future. This was one of the many issues the U.S. Food and Drug Administration advisers discussed at their meeting this week.
CNN: If people are entitled to boosters now, should they get them or should they wait?
Whom: It depends on the individual’s medical circumstances and how much they are willing to give up to avoid Covid-19, as I mentioned in our CNN Q&A last week. Someone who is over 65 and/or immunocompromised should probably get the extra boost now.
On the other hand, someone who is between 50 and 65 years old, has no medical problems and has recently had Omicron infection could probably wait. Some people may put off an extra booster shot while they are well protected from serious illness. Others want to avoid any infection, even mild and asymptomatic infections. These are all personal decisions that must be made in consultation with your healthcare provider.
CNN: What’s your booster advice for people under 50? Should people get their first refresher? And should they go for their second?
Whom: Everyone should get their first booster if they are eligible. The question of the second booster is more complex. If the person is under 50 and moderately or severely immunocompromised, they should also get their second booster shot. Another group who should get their second booster shot, even if they are under 50, are those who have received two doses of the Johnson & Johnson vaccine and it has been at least four months since their last dose. All other groups under the age of 50 are not eligible to receive their second refresher at this time and should not opt for their second.