Do I Need a COVID Vaccine Booster?
For the general population, vaccine boosters are not needed simply because vaccines are so effective
The Biden administration and Health and Human Services recently announced that they would make COVID vaccine booster shots available to all Americans by September 20th. This was an odd announcement because it is not a recommendation made by the FDA, which is where we would typically hear such news. The announcement was also not accompanied by any reference to any specific study or research that would suggest this course of action. There were references to “analyzing the scientific data closely” but no indication of which data, specifically, was being referenced. Despite this, they said that “a booster shot will be needed to maximize vaccine-induced protection”.
This started a lot of questions about what boosters are and who needs them. I’ve tried to summarize here the current evidence surrounding boosters and then give a glimpse into my own reasoning for what I’m going to do about vaccine boosters.
Shots In The Dark
It’s important to remember that we’re still operating with a lot of half-complete information when it comes to the ideal strategy for vaccine application. Even the people in the initial COVID vaccine trials have only been vaccinated for about 12 months, so there are a lot of questions about the long-term durability of vaccine immunity.
The case for a third dose of vaccines rests on the fact that a third shot applied several months after the second dose has been shown to increase antibody response roughly three times as high as the second dose. This information is then combined with the knowledge that higher antibody response is fairly well correlated with a better immune protection. The case in favor of booster shots rests on these two pieces of knowledge set side by side.
The missing piece in all of this is the fact that, while studies involving a booster shot certainly show higher antibody response, they have not yet shown that this results inis higher efficacy. When it comes to antibodies and protective efficacy, there seems to be a diminishing return on simply having a higher concentration of antibodies.
If we take the antibody response from natural COVID immunity (getting sick from COVID and then getting better) as our baseline, we can observe that the vaccines produce antibodies 2-4 times higher, but that only results in an additional 5-10% increase in protection against future infection.
Adding a third shot to this may increase antibodies to 12 times the rate of natural infection, but we don’t have any data yet on how much that increases protection. The use of boosters is more of a “better safe than sorry” attempt at reducing infection, an educated guess that more antibodies will help, but it’s still a guess that isn’t really backed up with research quite yet.
Increasing a protection rate from 95% to 97% would generally be considered not worth the trouble of providing a third vaccination, especially since these protection rates have error bars that are more than 3%. However, there is a possibility that we are seeing a waning of protection against infection when we look at vaccinated individuals and their response against the original COVID strain vs the Delta variant.
Scientists Like To Know Things
If you really want to dive deep into the questions and the rationales behind boosters, I highly recommend watching this video of the ACIP (Advisory Committee on Immunization Practices) meeting on the use of COVID booster shots. Start at 37 minutes to hear the discussion on booster shots.
The ACIP is a group of medical experts who are independent of the CDC but will provide recommendations to the CDC on the best path forward for vaccine application and use. Their discussion was informative and comprehensive, and it’s really quite exasperating that the discussion within this meeting is not the driving narrative around vaccine booster recommendations.
In their review of the data, they found that while there has been some decrease in protection against all infection between Alpha and Delta, vaccination remains robustly protective against symptomatic infection, severe disease, and hospitalization.
Where there is a drop in protection, it is largely among the elderly and “medically frail” patients, such as those who are in long term care facilities.
There were a number of other concerns brought up in the ACIP discussion, such as the feasibility of administering third doses as well as balancing the safety of a third dose against the potential benefit. A lot of these questions were answered with “We are not comfortable making a sweeping recommendation because we don’t yet have the data to answer the questions before us.”
One thing that they were keen to point out is that we have several existing vaccine schedules that use three doses but do not require annual booster doses. I got the sense in listening to this discussion that there was worry within this group that a focus on booster shots would interfere with the strategy of getting people vaccinated with first shots, which is where our focus should remain.
The recommendation that came out of this discussion was that, even without the final safety and efficacy data available, booster shots are probably a good strategy for elderly or immunocompromised individuals. For those populations, the risks of the disease are still high enough that it’s worth operating in a bit of a fog. And, indeed, this is the conclusion that doctors have already begun to enact. Florida has recently begun tracking booster shots of the vaccine and has administered almost a quarter million of them targeting the most vulnerable population groups.
However, even with Delta, there seems to be no decrease in protection against severe disease or hospitalization for the vast majority of adults, so adding another dose isn’t likely to improve the overall protection that vaccinated individuals already have.
This is where the political and media focus on booster shots caused a low simmer within the ACIP discussion group. The White House has put a lot of focus on boosters, promising to make them available to everyone by September 20th and implying that they were looking at data that showed boosters are necessary. This very much riled the ACIP group because the administration was making recommendations that weren’t coming from an expert panel or a vaccine recommendation group and implying that they had special access to knowledge that, in their understanding, simply did not exist. One physician gave this very careful but pointed rebuke to the White House, gently suggesting that it’s not helpful to suggest that there is some secret data that they are using to make decisions when that data does not exist.
“When the White House or HHS made that Sept 20th availability, it led everyone, it led physicians, it led the public to believe that they had access to information about these vaccines and the need for boosters that had not yet been publicly released. That opened the door to a lot of confusion. Then when we hear today about threatening providers with the PREP act… we need to all go in the same direction to get everyone vaccinated, to get everyone protected, and to keep everyone protected and not to waste this precious resource.”
This might seem like a trivial complaint but it really is important that the White House not get out ahead of the research and make their own policy recommendations based on incomplete research.
Worrying Trends
I’ve been carefully trying to follow the ins and outs of FDA guidance and recommendations, and the language from the White House of “needing” booster shots came out of left field without hard data to justify it. It stated that it was contingent on FDA conducting an “independent evaluation and determination of safety,” but the simple act of making this announcement puts an enormous amount of pressure on the FDA to come to a specific conclusion on an arbitrary timeline. This isn’t just pundit-speak for something I don’t like; the two senior FDA officials in charge of approving this plan resigned days after the announcement.
Additionally, there has been a worrying trend in which, soon after something is officially recommended, it quickly becomes mandatory. We can see this in Israel, where the definition of “fully vaccinated” has already been changed to include a third booster shot. It feels like the road to ending COVID restrictions is being artificially pushed backward even for people who have “played by the rules” or who are at extremely low risk.
Stop Yapping and Tell Me: Should I Get A Booster Shot?
Absent the politics and the formal recommendations on booster shot administration, there is practical application of “Should I get a booster shot?” The best way I know how to answer this is to explain what I would recommend to my family. For myself (a relatively fit millennial), I’m confident in the efficacy of the vaccine I’ve already had and, unless I’m part of a research trial, I’d rather see some kind of data on the actual impacts of a third dose before I take it. However, for my grandmother in her late-80’s I may recommend a “better safe than sorry” approach simply in an abundance of caution.
Fortunately, this seems to be the way things are already being run. Physicians have the authority and ability to recommend a third shot for patients they consider to be high risk and those shots are already being administered. Given that reality, the political fight over this topic seems incredibly pointless.
I thought this fight has reached its peak, but Monday saw the publication of this Politico piece which is heavy on talking about the political infighting between the Biden administration and the FDA, implying that the CDC has hidden data that supports boosters that they don’t want to show the public. It seems like more of a pissing war over who gets to run the narrative and call the shots (ho ho ho, I’m so funny). It seems like the booster announcements were made more in a spirit of “we need to do something, anything” than in deference to careful research and institutional recommendations.
Looney Tunes: Hair-Raising Hare (1946)
Bugs bunny is lured by a mechanical femme-bot into what is clearly a haunted castle by a Peter-Lorre-type evil scientist in order to introduce Bugs to his giant red monster for reasons that are somewhat opaque. I mean… obviously the reason is so Bugs can have a big chase scene in a haunted castle with a giant red monster, so I suppose we must forgive the thinness of the conceit. The gags here are good and the ending is sublime, where we discover that the monster is afraid of people and Bugs is forever a sucker for the dames.
Hey Matt, So just a bit of weird data point. I got the J&J got Covid. I've got a lot of people in western in central mass with moderna and pfizer that are getting reinfected, all got our shots in that march-april timeframe. VERY light symptoms, i really didn't need to be out of work but my company has a 10 day policy and so does the state I live in (work out of state). I'm not sure where this all ends but with our vaccine rates in Mass I'm not real sure where this leaves us.
A nit: The chart you show does not show that "the vaccines produce antibodies 2-4 times higher" than previous infection. It shows that the *most effective* vaccines do. There are three other vaccines that are below "convalescent" on the chart.
To another point, if we ignore the error bars, increasing protection from 95% to 97% is actually pretty significant, since it decreases infections by 40%. In fact, as a policy matter, I'd say it's a pretty good bet that third doses for the elderly and other high-risk populations are going to be more useful than second doses for the "young and healthy" demographic.