Vax facts: Why do I need a second Pfizer jab?

GARDEN ROUTE | KAROO NEWS - While many people get their second Pfizer vaccine 42 days after their first one, as per Department of Health guidelines, a significant number of people are yet to return for their second jab.

1. If you receive a Pfizer vaccine, you will need two doses to get full protection from severe illness and death. This is not unusual; other vaccines, such as those for measles and hepatitis, are also administered in two doses.

2. The first Pfizer dose primes your body's immune system by introducing a small piece of genetic material (mRNA) into your muscle cells. This mRNA causes your cells to make copies of the spike protein, which is like the SARS-CoV-2, but is not harmful.

3. Having done its job, the mRNA breaks down in a couple of weeks. It doesn't go anywhere near your own DNA (which is inside the walls of the nucleus of each cell).

4. Your body reacts to the spike proteins by producing antibodies, which give you some protection. While this happens, you may feel flu-like symptoms.

5. The second dose activates other parts of your immune system - especially T-cells, which "remember" the spike protein and quickly bring in other cells to fight the virus if you get infected. That is why, if you are reinfected, you are likely to be only mildly ill.

6. You must get your second Pfizer dose about 42 days after your first dose. If you miss your scheduled appointment, go to a vaccination site near you as soon as possible.

7. Johnson & Johnson (J&J) has produced a single-dose vaccine, but you may need a booster dose in future. The booster will increase protection and extend the duration of protection.

8. The scientific community is investigating a mix-and-match booster shot strategy. This could see people receiving different vaccines in their first and second jabs.

9. Both the Pfizer and J&J vaccines have been found to be safe. In the rare instances that people have serious reactions, these are quickly treated by healthcare workers.