Does a vaccine provide additional protection to a previously infected and recovered patient? [closed]

Question

The change in literature I've observed during the covid-19 pandemic is certainly prompting this question, but I think the question can be answered broadly in terms of immunology, which does have decade after decade of study, rather than the currently unfolding event.

Here's the claim from various sources, yes they're all about covid, I've yet to read the claim for another disease... but plenty more around covid still, if these aren't enough

CNBC

CDC

Some other 'health' website

These all state you should be vaccinated regardless of previous infection.

To be clear, I'm not asking if it's better to get the vaccine or to get infected, obviously avoiding a potentially fatal, easy to spread disease is the better option - but if you've already been infected and recovered, I've always read that the naturally occurring immunity far exceeds that of immunity gained from a vaccine.

In the case of measles it's well documented the vaccine immunity is sub par to survivors - it was still a huge boon to society, created enough immunity to eliminate the disease in our country (yay vaccines!) until the anti-vax movement led to a critical number of parents deciding not to vaccinate their kids and allowing a recurrence (boo anti-vax).

Again looking at measles, amongst numerous other diseases we vaccinate for, it's well documented that contracting and recovering from the disease provides life long immunity. This article does outline an improperly vaccinated population that could catch it, but also supports the life long immunity claim in recovered patients.

I've only ever read this generally, haven't found good primary sources, and assume it will vary by disease to some extent? But really have no idea, please help out with any evidence.

So is there any evidence that shows a vaccine will provide additional protection against an infection the body already has a natural immunity to?

EDIT: I'm not looking for an expert opinion, strictly hard evidence that shows this. I can find plenty of videos of Fauci saying how important it is. Just haven't seen anything that actually backs it up.

Answer 1

Your question cannot be answered broadly. Different viruses are different challenges - the flu, for example, isn't magic, it's just evolved to be incredibly fast at changing (the flu virus genome is in a bunch of tiny pieces that let it quickly swap out parts to find combinations that the population is naive to). HIV is an entirely different challenge for your immune system to respond to.

For COVID-19, there is evidence that the vaccine boosts the immune response to people who have recovered from COVID-19 infection.

https://immunology.sciencemag.org/content/6/58/eabi6950

In contrast, all SARS-CoV-2 recovered individuals had detectable levels of anti-spike and anti-RBD IgG at baseline, and these antibody responses were significantly increased after the first dose of vaccine (Fig. 1B). However, in SARS-CoV-2 recovered subjects, there was no additional increase in antibody levels following the second vaccine dose (Fig. 1B). Notably, the levels of anti-RBD IgG were similar in the SARS-CoV-2 naïve and SARS-CoV-2 recovered individuals at 1 week post-boost (timepoint 4) (Fig. 1B).

This is additional protection. Immune response varies widely individual to individual after recovery, but is enhanced by vaccination in all individuals in the small cohort tested.