Covid-19: boosters and tests, what you need to know

New Zealanders waiting on tenterhooks to see how bad the Omicron wave will be are being told to prepare for the virus by getting their booster shot of the vaccination, and to get a test if you have symptoms. But why is the booster so important – and if everyone’s going to catch Covid-19, do we really need a test? Dr Nick Bakerchief medical officer for Nelson Marlborough Health, explains.

Getting Boosted

I have had my Covid-19 vaccinations, and I’m a healthy person, so why do I need to also get the booster?

The Covid-19 booster will improve your protection especially against the Omicron variant. It will reduce the chance of you transmitting Covid-19 to others as well as reducing the chances of you getting seriously ill. It prevents the decline in immunity that occurs months after the second dose.

It further “trains” your immune system to make your body an incredibly difficult and hostile environment for the virus. The virus may still stick in your nose, but the immunity developed after vaccinations makes it much less likely to get into your blood stream creating a whole body severe illness.

READ MORE:
* Omicron NZ: Why the daily Covid-19 data will soon be a bit of a muddle
* Covid-19 NZ: Is it really a good idea to call Omicron’mild’?
* Covid-19 NZ: Omicron is here. This is what happens next
* Covid-19: Omicron is a real danger, but it could also put brakes on the pandemic

If vaccinated people can still get Covid-19, why is the vaccine important to prevent spread?

It is still possible to get the infection after the vaccination. However, infections in vaccinated people are usually milder with fewer symptoms, and they do not last as long. Any illness is likely to be shorter with fewer symptoms which reduces the chances of the virus spreading. The worst spreading of the virus occurs when “propellant” in the form of coughs and sneezes forces it out of the nose and chest into the air for others to catch.

I have already had Covid-19, can I get it again?

Just like cold viruses Covid-19 changes. Each time you get a cold it is not the same variant you had previously. People who have had Delta can (and have) still contract Omicron. Vaccinations do seem to give a better protection than having had the virus.

Each time we prime our immune system by exposure to the virus, variants and / or vaccine it gains “experience and competence” to manage the next encounter better with less risk of serious illness.

If Omicron is a milder illness why are we still worried about it?

For many people Omicron is a milder illness than earlier variants of Covid-19. However, this is not always the case and some people do still become severely ill and some die. An extra problem with Omicron is that it is extremely infectious, so very large numbers of people will get ill at the same time causing high demand for health services and major disruption because many people are away from work.

Although the virus may be present in the community by reducing the transmission of Covid-19 there will be less demand on our healthcare system. We have seen many other countries where these problems rise to unmanageable levels.

Getting tested

We are being told Omicron will spread and to be prepared to get sick, so why do people still need to get tested?

It is important to get tested if you feel unwell even with mild symptoms that could be Covid-19, including backache, headaches and cold-like symptoms. Testing is particularly important if you have been in contact with a person with Covid-19 or at a location of interest. Once tested, you need to keep isolated until your results are known and you are advised to mix again.

By slowing the spread at this time we are giving people time to get the booster shots, and whānau time to get their tamariki vaccinated. Slowing the rate of spread also reduces the pressure on the health services so they can keep pace with demand – flattening the curve.

If progression of Omicron is not slowed we risk having a higher peak than our health system can cope with, putting us all at greater risk from Covid-19 as well as disrupting and delaying all other types of health care. high levels of illness which will have severe impact on industry and businesses.

I know my body, and it’s definitely hay fever / a mild cold / backache – so why bother testing?

Omicron can present very similar symptoms to those of a cold, hayfever or flu. If you display any of these symptoms it is still important to get tested to rule out the possibility of Covid-19 (Omicron or Delta) as it is highly contagious.

I definitely know I caught it from my friend / neighbor / partner, and they got tested and were negative, so I don’t need to get a test.

Because the symptoms are common to other illnesses it is possible for Covid-19 to be mistaken for other illnesses. Testing will confirm if it is Covid-19 and we can identify possible spread to slow transmission.

I haven’t been to any locations of interest, so I can’t have been exposed.

Omicron can display little or no symptoms, but it is still very contagious, so although locations of interest are important, as community spread accelerates it will be possible to catch the virus without any known contact with a case or location of interest.

The result takes too long to come back, I’m not going to isolate if I don’t need to.

To protect others it is very important to follow instructions and isolate once you have been tested, until you are advised that you can mix. Sometimes it is necessary to keep in isolation even after a negative test. Tests are negative during the incubation period of the infection.

The test is horrible, and I’m scared of it hurting – I’d get it if it was the RAT or a saliva test.

RATs only detect the virus within a small window during the virus lifecycle compared with that of a nasal swab. However, they do not detect the virus as accurately as the current tests.