What Are These Updated Boosters?
These bivalent vaccines are called “updated boosters” by the FDA. They contain two messenger RNA (mRNA) components of the SARS-CoV-2 virus, which is the culprit of the COVID-19 pandemic. One component is the ancestral strain of SARS-CoV-2, which was isolated and sequenced from Wuhan, China; and the other is the mRNA shared by the BA.4 and BA.5 sub-lineages of the Omicron variant.The mRNA in these vaccines is a specific piece of genetic material that instructs cells in the body to make the SARS-CoV-2 spike protein that will trigger an immune response inside the body.
The Pfizer-BioNTech COVID-19 bivalent vaccine is authorized for use as a single booster dose among individuals 12 years of age and older. The Moderna bivalent vaccine is authorized to be used among individuals 18 years of age and older, also as a booster vaccine.
Do Bivalent Vaccines Have Higher Efficacy Than Monovalent Vaccines? Not Likely
The new bivalent vaccines (updated boosters) contain an mRNA component of the ancestral strain, which has already disappeared and been replaced by many variants. One may wonder: why do these new vaccines contain the genetic information of a strain that no longer exists, especially when they were designed to prevent the Omicron variant infection? There are possibly several reasons.Furthermore, scientists and researchers have always been trying to predict the next variants to emerge. So if the upcoming variants are closely related to the original strain, then the bivalent vaccines would make sense. However, the future is difficult to predict, and nobody can say for sure what the next variants will be like.
According to the general trend of virus development, the COVID-19 virus is constantly breaking through the limitations of its transmission. As it’s becoming increasingly transmissible, its pathogenicity is also decreasing. Therefore, the virus is now becoming more adapted to a long-term presence in human societies. So, it’s unlikely that the virus development will reverse its trend for the next variant to become more close to the ancestral strain than the rest.
In fact, monovalent vaccines can protect against different COVID-19 strains, although they focus on one particular strain. For instance, the BA.1 monovalent vaccines were manufactured in early 2022 to target the BA.1 sub-lineage. In practice, however, these vaccines can also target the original strain to a certain extent. This is because the virus’s targeted mutations are at the individual protein loci, but the virus itself has many antigenic parts on different proteins that are very similar to the original strain. Therefore, even after receiving the monovalent mutation vaccine, the body will still be able to produce antibodies against the original strain. Similarly, monovalent vaccines focusing on the ancestral strain can also produce antibodies against various mutant strains, to a certain extent.
Overstock and Wastage of the Original Vaccines: the Real Reason Behind Bivalent Vaccine Development?
When producing the bivalent vaccines, the original-strain based vaccines produced by Pfizer and Moderna can be used.The conversion of the original COVID-19 vaccines to the new bivalent booster shots can potentially reduce the stockpile or wastage of these vaccines. Therefore, it makes commercial and financial sense, especially for the vaccine manufacturers and some national governments, who’ve made massive-scale purchases of such vaccines.
The U.S. government has previously pledged to donate 1.2 billion doses of vaccines, but so far, only less than half have been distributed. According to White House Press Secretary Jen Psaki, the vaccines are becoming more difficult to place, due to the full reserves of other countries. In order to fulfill its pledge, the U.S. government is now sending some pediatric doses, for which the demand is higher, instead of adult Pfizer vaccines. Overall, the demand from other countries is dwindling.
Therefore, given the large amount of soon-to-be expired original vaccines, converting them into (potentially) in-demand bivalent vaccines can effectively prevent wastage.
In summary, there are relatively large stockpiles of unused monovalent vaccines currently stored in government warehouses, or the government has already paid and placed orders for more such vaccines. These vaccines might have been partially produced and are currently sitting in the vaccine companies’ warehouses. What will happen to these vaccines? Some of the vaccines that were produced too early will also face expiration.
Are the governments implementing bivalent vaccines now to help the vaccine companies or the governments themselves to solve the stockpile problem? The production of these mRNA vaccines has used a lot of resources, and they may feel it would be a shame to waste them in this way. So we can’t rule out the possibility that the authorities will buy bivalent vaccines in order to save resources from being wasted.
No Clinical Data Available for Newly Authorized Bivalent Vaccines
Although the FDA has authorized the use of the Pfizer and Moderna bivalent boosters targeting BA.4/5, these vaccines don’t have clinical data. And human data are only available for their bivalent boosters targeting the BA.1 subvariant. According to the companies, clinical trials for the BA.4/5 bivalent vaccines will start in September 2022.For the BA.4/BA.5 boosters, both companies have submitted only animal data to the FDA, but they haven’t been released publicly. It is only known that at the June 2022 FDA meeting, Pfizer presented their preliminary findings regarding their bivalent vaccine. However, these data are based on only eight mice which were given the vaccines as their third dose. Compared with the original vaccine being used as a booster, the updated boosters have provided the mice with an increased response to all Omicron variants tested, including BA.1, BA.4, and BA.5.
One may wonder: how can the authorities authorize vaccines without human trial data? First, these bivalent vaccines have only been approved for emergency use authorization. In order to obtain the FDA’s full approval, clinical data are a must. Another way is to produce COVID-19 vaccines in the same approach used in the production of influenza vaccines.
Flu vaccines are updated each spring, by predicting the strain that will become prevalent in the fall and winter. Such updated vaccines don’t need new clinical trials to receive approval, unless the manufacturers significantly change the formulations. It can be argued that when producing updated COVID-19 vaccines targeting a specific new variant, the changes to the mRNA used in the vaccines are small, so there’s no need for new clinical trials. Therefore, producing updated vaccines without costly human trials can save both time and money.
Nevertheless, authorizing the use of vaccines without clinical data can lead to lower acceptance by the public, since people won’t be able to know the potential side effects or adverse events until they receive the jab.
Will the Vaccines Be on the Commercial Market?
On August 11, 2022, the CDC reversed its COVID-19 guidelines. The CDC now recommends people to take personal responsibility to choose their own prevention behaviors, based on their own risk for severe illness and their risk tolerance. Also, as breakthrough infection can take place after vaccination, the COVID-19 prevention recommendations no longer differentiate, regardless of vaccination status. For instance, quarantine of exposed persons is no longer recommended, regardless of their vaccination status.In the previous months, many people were forced to leave their jobs or stay away from certain places such as universities and schools, since they were unvaccinated. Many people got the COVID-19 jabs in order to go to work, participate in social activities, and travel. However, according to the current CDC recommendations, the vaccination status should no longer be a consideration. In this case, many people will likely choose not to receive the boosters.
So, what will this mean to the vaccine industry, especially the COVID-19 vaccine manufacturers that have made a fortune during the pandemic?
During the pandemic, the FDA used its EUAs to make many COVID-19 vaccines available to the public, instead of using its regular approval process. Now with new COVID-19 cases in decline and the pandemic seemingly coming to an end, will the federal government create a permanent mandatory program to cover vaccines?
Once on the commercial market, the vaccine and pharmaceutical companies may then raise their products’ prices.