The past three years have taught us a hard truth: Covid-19 does not pose the same risk to everyone it infects. Now, US public health agencies are trying to align Covid-19 vaccination recommendations with this fact.
This week, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices rolled out simplified vaccine recommendations aimed at helping people figure out what to do now.
Specifically, the guidelines elevate the bivalent vaccine – introduced last fall as a tool to train immune systems to protect against older and newer strains of the virus – from “booster” status. According to the new recommendations, the bivalent vaccine can be used as the first and only vaccine a person receives as the primary vaccine.
The new guidelines apply to updated bivalent formulations of mRNA vaccines produced by Moderna and Pfizer-BioNTech. The original series of vaccines that most Americans received earlier in the pandemic are no longer available: earlier monovalent formulations from Moderna and Pfizer are no longer licensed in the United States, and others, such as Novavax and Johnson and Johnson’s, have been used here only rarely.
The result: for now, to be considered up to date, everyone should have at least one bivalent vaccine. However, only those at high risk should receive repeat bivalent vaccinations.
Additionally, while previous vaccination with the older monovalent version of the vaccine was a prerequisite for bivalent vaccination, under the new guidelines even people who have not received any Covid-19 vaccine can receive a bivalent injection.
Uptake of the bivalent vaccine has not been great in the United States. Only 42% of people aged 65 and over – who are most at risk of serious illness and hospitalization due to Covid-19 – have received the vaccine. In total, less than 17% of all Americans have received a bivalent vaccine. In a statement, FDA Center for Biologics Evaluation and Research Director Peter Marks said, “The agency believes this approach will help encourage future vaccination.
It should be noted that the FDA and CDC have used “may” not “should” language in most of these guidelines (with one exception). At this point, these agencies are avoiding language that suggests anyone who’s ever been vaccinated “should” get another one. That’s because the data on repeat vaccination isn’t strong enough to justify telling anyone they need to get vaccinated again. Instead, the CDC and FDA emphasize who is simply “eligible” for more doses.
Here is the result of the latest recommendations.
If you are a healthy person between the ages of 6 and 64 who has ever received a bivalent vaccine
This one is the simplest: The FDA has said that for most people age 6 and older, one dose of the bivalent vaccine, regardless of when they received it, is sufficient for now.
It’s not that repeat vaccination wasn’t protective against hospitalization in this age group last fall and winter, the CDC said — it was.
But lately, the risk of hospitalization has been so low among children and adults in these age groups, and the protection afforded by repeat vaccination has been so short-lived – lasting only about two months – that bivalent vaccination repeated would end up being of little benefit in this group.
If you have never been vaccinated or have only aged, monovalent versions of the vaccine
The CDC has made its strongest and most explicit recommendation for people who have not yet received a bivalent vaccine – whether because they have not yet received Covid-19 vaccines or because they only got original, monovalent versions of the vaccine that were available before August 2022. Those people should get a bivalent vaccine now, the agency said in a news release. That goes for everyone ages 6 and up — and with so few Americans ever having received a bivalent vaccine, that’s the category the most fall into.
For people who are still unvaccinated, the reasoning is that while they may have some immunity to Covid-19 due to previous infection – at this point most people have been exposed to the virus – it’s usually less protective against serious disease than the broader protection that seems to come from being both immune to and cured of infection.
For people who have only received monovalent versions of the vaccine, the reasoning is that there is protection in the bivalent vaccine not only against the original strain of the virus, but against newer variants of omicron, BA.4 and BA.5. And although very few of these strains are now circulating in the United States, they are still genetically closer to the current strains than the original virus.
Therefore, a vaccine that trains the immune system to recognize earlier and later strains of the virus is thought to provide better protection than a vaccine that only targets earlier strains.
If you are 65 or older
People 65 or older can also get a bivalent vaccine now, even if they’ve had one before. For this group, the rationale for the FDA’s recommendation is that people 65 and older continue to be hospitalized with Covid-19 at higher rates than younger adults. During the fall and winter, people in this age group who had received bivalent vaccines died at much lower rates than those who had not. For this group, the FDA has recommended waiting at least four months after the most recent bivalent dose to obtain a repeat dose.
If you are moderately to severely immunocompromised and 5 years of age or older
According to the CDC, “moderately to severely immunocompromised” people include those who are or are about to be treated for cancer or receive organ transplants, those who have advanced or untreated HIV, and certain immunocompromised congenital diseases, and those taking a variety of immunosuppressive treatments. medications.
If you are moderately to severely immunocompromised and age 5 or older, you can also receive a bivalent vaccine now, even if you have received one before. (Immunocompromised children under 5 are not eligible for a repeat bivalent dose under the new FDA recommendations because the agency did not have data to support it. Several pediatricians at the CDC meeting this week expressed concern that this decision leaves a very vulnerable group unprotected.)
There are several reasons for this recommendation. For starters, this group may not have as robust an antibody response to Covid-19 vaccines. But another problem is that monoclonal antibody treatments — which once provided an extra layer of protection for immunocompromised people — no longer work against omicron variants and are no longer FDA-cleared except in unusual cases.
The FDA has recommended that immunocompromised people wait at least two months after the most recent bivalent dose to receive a repeat dose. They also said that people with certain types of immunosuppression – such as those receiving or about to receive a stem cell transplant, drugs that lower B-cell levels, or treatment with CAR-T cells , a certain type of cancer treatment – may continue to receive repeated doses. every two months in the future. People in this category should discuss with their health care providers what is best for them.
Children 6 months to 5 years old can receive bivalent doses if not vaccinated
Different manufacturers have different dosing schedules and different age thresholds for pediatric versions of their bivalent vaccines: Moderna’s pediatric vaccine is given in a two-dose series for children 6 months to 17 years of age, and Pfizer’s is given in a series of three doses for children. 6 months to 4 years. Thus, when it comes to children, it is less complicated to speak of complete or partial series than of number of doses.
Under the new guidelines, unvaccinated children can go straight to the full series of bivalent vaccines, just like healthy young adults. Meanwhile, children who have received the full or partial series of older monovalent vaccines may also receive at least one dose of bivalent vaccine. (The number of doses will depend on the number of monovalent doses received and the manufacturer. Parents should ask their pediatrician what to do for their child.)
Prepare for more changes to come
This fall, when manufacturers likely release updated versions of the bivalent vaccine designed to protect against the latest virus variants, recommendations will likely change again.
But until then, the new guidelines outline a game plan for most people on how best to protect themselves using vaccines.