It was compiled by experts Lucy Allais, Shabir Madhi, Imraan Valodia, Alex van den Heever, Martin Veller and Francois Venter.
Vaccines are our best hope in fighting Covid
After 18 months of worldwide infection and deaths and with 10-15% of survivors experiencing the unpleasant “long Covid’’ symptoms, as well as severe social, economic, and educational disruption, it is clear that the novel coronavirus, SARS-CoV-2, which causes COVID-19, is not going to go away. But, as terrible as the pandemic has been, the good news is that a number of very effective vaccines have been developed.
Our only hope for getting the COVID pandemic and its severe health, social and economic consequences under control, is for as many people as possible to be vaccinated against it as quickly as possible.
How do vaccines work?
Our bodies have many processes that detect and fight infection and disease: together these are called the immune system. When our bodies become infected, some cells figure out how to fight the infection, and if they are successful, and we survive, our bodies develop the memory of how to produce these cells that know how to fight this specific infection, usually far more efficiently and speedily the second and subsequent time round. This is called immunity.
Vaccinations are a way of triggering the body to develop an immune response to a particular disease without having to actually get the disease — a kind of fake first infection.
Vaccines are one of the most successful, and safest, interventions medicine has ever created. They have eradicated dangerous infectious diseases such as smallpox, have controlled polio, and have saved billions of lives from measles, tetanus, pneumonia, hepatitis and diarrhoea. They have dramatically decreased viruses responsible for some cancers. They are also safe — bad side effects are very rare and the risk of developing severe illnesses is much smaller than the bad effects of the diseases the vaccines prevent.
Vaccines were not invented by Big Pharma, and are not unique to Western medicine. The first recorded use of something similar to vaccination was in China in the 16th century.
Will I immediately have protection?
No. Immunity takes time to build up in the body. For most COVID vaccines, it takes at least two weeks after the vaccine has been administered for you to start developing immunity. Most vaccines will start providing some protection against severe illness two weeks after the first dose. However, good protection generally requires at least two doses of the vaccine, and will start materialising 7 to 14 days after the second dose.
The different COVID-19 vaccines
All vaccines work very well against severe COVID, irrespective of the variants (different versions of the virus) that are circulating. They differ in how well they protect against infection and mild COVID (usually sniffles, tiredness and other flu-like symptoms).
At the moment, two vaccines are being used in SA — both excellent choices:
• Johnson & Johnson (single shot)
• Pfizer (two-dose schedule, several weeks (minimum three weeks) apart).
Other excellent options, mostly two-shot, are being evaluated. Don’t stress about which one is best — the best one is the first one you can get.
Even though you’ve had a vaccination, you should continue to act as if you do not have immunity until three weeks after your first (J&J) or second shot (Pfizer).
Do not assume you have enhanced immunity straight after getting your jab. Continue to take precautions. Mask when indoors with people and always open windows in rooms and vehicles.
How safe are you once you are fully vaccinated?
All the vaccines currently used give excellent protection against severe illness and death — they keep you out of hospital and off a ventilator.
We have less good information on how likely you might be to get a mild infection of COVID, and it is possible that you could get infected. We have seen many people get mild “breakthrough’’ infections even after the full two weeks after vaccination. Often this will be so mild that you don’t know you have it; some people get worse infections which can feel like a bad cold, but they usually recover after two to three days.
Even though it’s possible to get COVID mildly once fully vaccinated, we now know that fully vaccinated people are less likely to spread the virus. Also, vaccines will differ in how well they protect against infection and mild Covid, which also depends on which variants are circulating.
We are still learning how best to deal with these mild infections, especially with the new, hyper-transmissible Delta variant. It is possible we may need additional shots for better protection, whether of the same vaccine or a different one.
Should I expect side effects?
You may feel no effects at all. But side effects can include having a sore arm where you were injected, getting a headache, or having a fever, for a day or two. The side effects experienced are much milder than getting severe COVID (some of the authors have had this experience). Also, these side effects generally indicate that the vaccines are inducing an immune response and doing what they are meant to do.
Severe allergic reactions are very rare, but can occur after any vaccination; if they occur, the healthcare provider who administered the vaccine can immediately and usually effectively treat the reaction.
The Pfizer vaccine can cause an allergic reaction which is easy to treat, and very rarely can cause inflammation of the heart, which normally goes away quickly.
The J&J vaccine has a very rare effect of blood clotting, and can be serious; COVID causes this effect far more often though, so the benefits far outweigh the risks. Recently, the J&J vaccine has been associated with a very rare syndrome causing weakness, called the Guillain Barre Syndrome. This syndrome is also seen in patients who have had the flu and other viruses, and is treatable.
Are there any people who should not get vaccinated?
No. But some people may not develop as good immune responses from vaccines. For example: people with conditions involving immune suppression — like someone who has had an organ transplant and is taking immunosuppressant drugs to stop their body from rejecting the new organ; people on chemotherapy; or people taking immunosuppressives for other conditions like rheumatoid arthritis.
People with severe allergies may want to avoid the Pfizer vaccine, or ensure that the person giving the vaccination is ready in case of a reaction.
How long will immunity last?
We don’t yet know. It’s possible that we will need to get a booster vaccine every year or two to keep up our immunity. Modelling studies suggest that people might require booster doses every two to three years to protect against severe COVID. To protect against infection and mild COVID might require annual boosting. We will find out over the next two to three years.
The myth of ‘herd immunity’
Some commentators still maintain the aim of vaccination is to develop population-wide immunity, or “herd immunity”. This is when enough people have immunity that the microorganism stops being able to circulate at all. Herd immunity was an aspirational goal until the virus started showing the ability of mutating, causing it to become more transmissible and relatively resistant to antibodies induced by past infection and by vaccines.
Consequently, it is unlikely that herd immunity will be achieved with this virus any time soon, and it will probably circulate, mutate, and recirculate throughout our lifetime, reinfecting us several times, like all the other coronaviruses. Luckily, individual protection against severe illness is still possible with the current vaccines even with the mutations that have occurred. Those who do not get vaccinated will face an increased probability of infection and potential severe illness as variants of the virus continue to circulate. This risk will increase as society returns to normal.
But it is likely that everyone, unless they hide behind a wall for the rest of their lives, will eventually get the virus. It’s all about how badly you get it — whether you get it vaccinated or unvaccinated.
Do I need the vaccine if I have already had COVID?
Having had COVID definitely does provide short-term protection from severe illness, as the vaccines do, but there is no evidence that it is better than the protection acquired from vaccines (and the consequences, as we have noted, are severe). It is early days yet, and we will have more data to guide things, but we are aware of many cases, including among our colleagues, where people have had a second case of COVID, occasionally severe.
If you have had COVID, the good news is you have lots of protection from severe illness in the short term. However, adding a vaccine on top of this may well stimulate a slightly different response (and augment an already primed immune system), and mean you enjoy additional protection. The vaccines are very safe, and COVID does dreadful things, occasionally even in people with prior infection, so it is worth getting the vaccine as an additional precaution. One should wait for 2 to 3 months after having COVID before getting a vaccine, and you probably only require a single shot.
So until you and the people you interact with are all fully vaccinated…
Continue to wear your mask when indoors and to keep windows open. COVID is an indoor respiratory virus: it is spread in the air, and it collects indoors where windows are closed. You are unlikely to get it outside, and opening windows in rooms, cars, taxis and buses makes everyone much safer. As you are fully immunised only two weeks after receiving your second vaccine dose, take this into account when making decisions about interacting with people.