A preprint server medRxiv published a preprint article that analysed the level of antibody named anti-nucleocapsid antibody (anti-N Ab) post-infection in people vaccinated with the Moderna COVID-19 vaccine (mRNA-1273 vaccine) and compared the result with those who received a placebo. Referring to this article, several social media posts claimed mRNA vaccines impair long-term immunity after Covid infection. We fact-checked and found the claim to be Mostly False.
In April, 2022, a pre-print server named medRxiv published a preprint article titled, “Anti-nucleocapsid antibodies following SARS-CoV-2 infection in the blinded phase of the mRNA-1273 Covid-19 vaccine efficacy clinical trial”. Referring to this article, a Substack user wrote an article titled, “URGENT: The most powerful evidence yet that mRNA vaccines hurt long-term immunity to Covid after infection. A bombshell study – from the National Institutes of Health and Moderna, no less – should end debate”. This article began with the statement, “Unvaccinated people are much more likely to develop broad antibody immunity after Covid infections than people who have received mRNA shots, a new study shows”.
Do mRNA Covid vaccines impair long-term immunity?
It does not seem so. No evidence confirms that mRNA Covid vaccines impair long-term immunity. The preprint article referred to by social media users nowhere confirms that the mRNA vaccines impair long-term immunity after Covid infection.
The preprint article was conducted before the occurrence of Delta and Omicron variants. This article analysed the level of antibody named anti-nucleocapsid antibody (anti-N Ab) post-infection in people vaccinated with the Moderna COVID-19 vaccine (mRNA-1273 vaccine) and compared the result with those who received a placebo.
How are people diagnosed with Covid infection?
The available antibody tests for Covid assess proteins formed in response to either Spike protein or Nucleocapsid protein.
The mRNA covid vaccines recognize the formed proteins on the spike proteins to show a positive test for Covid infection in the cases with prior infection and/or vaccination.
However, the formed proteins can also recognize nucleocapsids. So, tests are available that can recognize these proteins on nucleocapsid to show a positive result for cases with prior Covid infection having a history of Covid vaccination.
Anti-N antibodies are produced when a person gets infected with Covid infection. Anti-N antibodies only recognize Nucleocapsid – a molecule present inside the Covid virus. Whereas, Anti-S antibodies recognize spike protein present on the surface of the Covid virus. Anti-S antibodies can be present within the body after a Covid infection and a vaccine. This is because mRNA from vaccines enters ‘the muscle cells and instructs the cells’ machinery to produce a harmless piece’ of the spike protein. The mRNA Covid vaccines do not promote the production of anti-N antibodies but recognize anti-S antibodies.
The preprint article has shown that 40% of vaccinated people formed anti-N antibodies at a median of 53 days after the diagnosis which was 93% in the placebo group. It seems, because the unvaccinated people had more anti-N antibodies after the Covid infection than vaccinated people, the preprint article claimed Covid-19 vaccines impair long-term immunity.
However, the article does not confirm if more anti-N antibodies provide strong immunity or if these antibodies confirm vaccines are effective against Covid infection. Also, the article did not confirm if Covid vaccines have any role in developing fewer anti-N antibodies after the Covid infection to impair long-term immunity.
Does the human body rely only on immunity from vaccines?
No. The human body experiences innate and adaptive immunity against viruses such as Covid.
Innate immunity is the defence system people are born with. It is the early response against the virus, which is then followed by adaptive immunity. Adaptive immunity is the process through which the body develops a stronger immune response against viruses using B and T cells. The B cells produce anti-S and anti-N antibodies.
The mRNA Covid vaccines target spike protein because it is where the virus attaches to the healthy cell and multiplies. So, the best thing is to inhibit the virus from attaching itself to the healthy cell, which mRNA vaccines do.
Besides spike protein, nucleocapsid also gets affected by the virus. However, from the perspective of mRNA Covid vaccine, spike protein is more important as it is the first point of contact with the virus.
A study has shown that vaccination against Covid infection and reinfection can reduce the number of anti-N antibodies. But this should not have any impact on the overall immunity.
Has India approved mRNA Covid vaccines?
In the trial phase. India has developed indigenous mRNA covid vaccines and may begin rolling out them soon for public use. This has made it essential to address the misinformation around mRNA vaccines prevalent in first world countries.
There is a list of already approved Covid vaccines in India.
THIP MEDIA TAKE: The available evidence does not suggest mRNA Covid vaccines impair long-term immunity after Covid infection. We need more studies to understand better the mechanism of mRNA Covid vaccines and the combined effect of all types of immunity against Covid infection.
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