“What are COVID vaccines for” is question a friend asked on his Facebook after the Ministry of Health posted this, “Vaccinated persons should continue to follow all current guidelines to protect themselves & others. This includes:
- Wearing a face mask
- Staying at least 6 feet away from others
- Avoiding crowds
- Washing hands often
- Following @MOH_Kenya guidance”
The reason the friend asked the question is the expectation that once someone gets vaccinated by one of the available COVID vaccines, they ought to get some permanent protection from being infected by SARS-COV-2, and that a vaccinated person is shielded from spreading the virus to others (after all if you can’t get the virus you can’t pass it on). That’s a very wrong picture about the vaccines. The vaccines do not work like condoms.
I have used two analogies when explaining how the vaccines work to friends – an umbrella (or a house or any other shelter), and a raincoat both of which are protection against getting wait from rainfall. An umbrella is the analogy that compares to a condom. It protects you against being rained on, just as a condom would protect you against contracting STIs, HIV included.
For SARS-COV-2, the closest we have to a condom are the MOH guidelines they have provided above, and a COVID vaccine isn’t part of the list. That is, you cannot think of COVID vaccine the same way you’d think of a condom when it comes to STIs and HIV. This however hasn’t stopped a medical doctor from advising a friend that he should think of COVID vaccine as a condom. The friend wrote, “Went for a blood test today , yes because my head won’t stop spinning and I asked the doctor whether one can get covid after being vaccinated. He said, it’s just like a condom people still get Aids but at least you are 98% protected”. Probably the doctor meant that just as condoms aren’t 100% effective, so are the vaccines, but the comparison is still very wrong.
Just as a condom is comparable to an umbrella against rainfall, so is raincoat comparable to COVID vaccines. A raincoat is piece of cloth that doesn’t protect you from getting rained on, but protects you from getting wet when you are rained on. This is the same logic used for vaccination against diseases. A vaccine doesn’t prevent you from getting the causative agent of the disease, but it prevents you from getting sick if the causative agent finds its way to your body.
In the case of COVID-19, the COVID vaccines are molecules tailored (using different technologies) to look like or mimick the functions of SARS-COV-2, so that those vaccines can cheat your body that you have been infected by SARS-COV-2. When the vaccine gets into your body, it triggers an immune response against the vaccines. Given that the dosage of the vaccine is such that a lot of the immune cells (mostly B-Lymphocytes and T-Lymphocytes) for fighting antigens that look exactly like the vaccine are produced and remain in blood circulation even after the vaccine itself has worn out, the body’s defence mechanism will be able to fight the actual virus in case the actual virus finally infects the body.
The above paragraph clearly explains that being vaccinated against SARS-COV-2 doesn’t prevent you from getting SARS-COV-2, but makes your body ready to fight SARS-COV-2 when it finally lands in your body. So it is important to think of vaccination as preparing the body to attack the virus when the virus finally gets its way into the body – similar to you going through internship to learn how to do the job, so that when you finally get the job, you have acquired performance mechanisms for executing the requirement of that job.
Are the vaccines safe? Yes they are safe. We know this because if you give the vaccine to 100 people, we are sure that none of those people will become fatally sick from the vaccine, and that if we give the vaccines to 1000 people, we are still are none of those people will get fatally ill from the vaccine. The vaccines were actually given to over 30,000 people during clinical trials and none of those tested became fatally ill from the vaccine; and although in the world trial there have been cases where people get fatally ill after receiving a dose of the vaccine, those circumstances have been 50 people out of 50 million people. Now, if you were to randomly collect 50 million people and observe them for a week as they go about their normal businesses, even without giving them anything, you can be sure that more than 50 of them will become fatally ill. Thus, when 50 out of 50 million become fatally ill after eating KFC, you cannot conclude that it is KFC that made them fatally ill – for you will be having 49 million, 999 thousand, 950 people who ate the food and turned out to be perfectly okay. The same reasoning applies to the Oxford/AstraZeneca vaccine.
Do the vaccines offer 100% protection? Yes and no. Yes because when the vaccine works on you, you become 100% protected. This protection isn’t protection against getting SARS-COV-2, but protection against getting COVID-19 in the event you get SARS-COV-2. Remember SARS-COV-2 is the virus that causes COVID-19. When can get the virus but doesn’t become sick. Such a person is said to not have acquired COVID-19 from SARS-COV-2.
The vaccine doesn’t offer 100% protection because, in the case of Pfizer / BioNTech vaccine, if you give the vaccine to 100 people, 95 of them are expected to receive 100% protection whereas 5 of them are expected to receive zero protection. It is this 5 to 95 ratio that made the researchers to report that the vaccine has a 95% efficacy against COVID-19 (not SARS-COV-2). In real world studies, the Pfizer/BionTech vaccine has been found to be 90% effective after double dosing, and 80% effective after single dosing.