More people can now receive second Covid-19 booster shots after federal health officials announced they are allowing a larger group to receive fourth doses of the two Covid-19 messenger RNA vaccines made by Pfizer/ BioNTech and Moderna.
Adults 50 years and older, who have already received three doses of mRNA, can receive a second booster dose if at least four months have passed since their first dose. Anyone who has received two doses of the Johnson & Johnson vaccine can also receive an additional dose of mRNA four months after their last booster.
Many people wonder: Does this mean everyone will need an annual Covid-19 booster? Do we need reminders even more frequently? Will it be combined with the flu vaccine? Will new vaccines be developed that target new variants? And should they wait to get the booster if they’re eligible, or get it now?
To help answer these questions, I spoke with Dr. Leana Wen, CNN medical analyst, emergency physician and professor of health policy and management at George Washington University Milken Institute School of Public Health. She is also the author of “Lifelines: A Doctor’s Journey in the Fight for Public Health”.
CNN: Will everyone need a Covid-19 vaccine every year?
Dr. Leana Wen: We do not know yet. There are a lot of variables here, and only time – and ongoing research – will tell.
First, we don’t know how long the immune protection from the vaccine and the first booster will last. There is plenty of evidence that the first recall is very important. At a time when Omicron was the dominant variant, three-dose efficacy against severe disease remained high, at 94%, according to a study by the US Centers for Disease Control and Prevention. If this protection begins to decrease significantly, it would be a sign that another booster is needed.
Second, there may be new variations that develop over time. The flu vaccine is given every year after being reconfigured every year for new mutations. Current vaccines work well against Omicron subvariants, but if there are future variants that evade vaccine-induced immunity, that is another reason for additional vaccinations.
Third, we need to monitor the prevalence of Covid-19. At present, it is still rampant worldwide, but if it eventually subsides, regular booster doses may not be necessary. As Dr. Anthony Fauci, President Joe Biden’s chief medical adviser, told CNN, “Is it going to get so low that we might not even need a shot? inch every year?” It’s possible, but we don’t know yet.
Fourth, we need to see if there is a clear seasonality of future Covid-19 outbreaks. Other coronaviruses that cause colds are more prevalent in the winter, as are other respiratory viruses like RSV (respiratory syncytial virus) and influenza. It’s likely SARS-CoV-2 is too, and there have been outbreaks in the winter months. This part, however, is yet to be seen in the upcoming fall and winter seasons.
Finally, there are logistical considerations to take into account. Adding an annual vaccine is a big undertaking. Flu vaccine uptake is already low; only about half of Americans get it each year. With the misinformation and polarization around Covid-19, encouraging this level of frequency will be big business.
CNN: Right now, a second booster is already allowed four months after the first, which means the current frequency is more than once a year. Could reminders be needed even more than once a year?
Magnifying glass: It’s possible. I want to point out that there are a lot of things 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. The first is that certain groups of people may need more frequent vaccinations. Remember that moderately or severely immunocompromised people have been recommended to get their extra booster for months. It is possible that in the future, certain more vulnerable populations will be asked to be vaccinated more frequently than the general population.
Additionally, there will also have to be contingencies if a new variant emerges that eludes prior immunity. There should be the ability to rapidly develop, manufacture and distribute variant-specific vaccines. If this happens, the frequency could end up being more than once a year for a period of time.
Going forward, we must also consider the availability of other therapies and mitigation measures. For example, Evusheld is an antibody infusion that, when given to immunocompromised people, is very effective in reducing their likelihood of progression to serious disease. Antiviral pills and monoclonal antibodies are effective treatments when given early in the disease. And there are other preventative measures, including masking and testing before encounters, that can also reduce risk.
CNN: If the The Covid-19 vaccine is going to be administered every year, would it be wise to combine it with the flu vaccine?
Magnifying glass: In theory, yes, but we just don’t know if the Covid-19 vaccine should be an annual vaccine.
There are other vaccines that last longer. The Tdap (tetanus-diphtheria vaccine), for example, requires a booster 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 will be three or four doses, and we’re done, or it may need to be updated more frequently like the flu. Again, we don’t know yet. If it ends up being something yearly and the seasonal pattern seems similar to the flu, it would be a good idea to have a combination vaccine – or at least get it at the same time as the flu shot.
VSNN: Why aren’t there any variant-specific vaccines that target Omicron?
Magnifying glass: Scientists are currently working on these vaccines. They are testing Omicron-specific vaccines and boosters to see if they might be even more effective than the original vaccines, which targeted previously dominant variants.
One consideration is that additional variants may arise, and scientists should consider whether Omicron-specific vaccines or the original vaccine – or a combination – will be most likely to be effective against potential variants in the future. It was one of many issues that US Food and Drug Administration advisers discussed at their meeting this week.
CNN: If people are eligible for boosters now, should they get them or should they wait?
Magnifying glass: It depends on the individual’s medical situation and what they are willing to give up to avoid Covid-19, as I mentioned in our CNN Q&A last week. Someone over 65 and/or immunocompromised should probably get the extra booster now.
On the other hand, someone who is between 50 and 65 years old, has no medical conditions and has recently had an Omicron infection, could probably wait. Some people may defer an additional booster as long as they are well protected against serious illness. Others want to avoid any infection, even mild and asymptomatic. These are all personal decisions to be made in consultation with your medical provider.
CNN: What’s your reminder advice for those under 50? Should people get their first reminder? And should they go for their second?
Magnifying glass: Everyone should receive their first reminder if they are eligible. The issue of the second recall is more complex. If the person is under 50 and moderately or severely immunocompromised, they should also receive their second booster. Another group who should receive their second booster, 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 50 are not eligible to receive their second booster at this time and should not opt for their second.