COVID-19 Update
General practice was extremely busy with COVID-19 cases in the run up to Christmas and over the New Year. The rate of new presentations has fallen significantly over the last 10 days due to the latest lockdown.
Here are some of your frequently asked questions answered:
1. Can I catch COVID-19 from a relative after they have had the vaccine?
No. It is not possible to catch COVID-19 from someone who has been vaccinated because of the vaccine. The COVID-19 vaccines are not derived from a live virus so there is no possibility of the virus spreading due to the vaccine.
The normal risks apply but a person does not become infected because of the vaccine.
It takes between 2-3 weeks for a vaccine to generate an immune response so a vaccinated person will still be vulnerable to catching COVID-19 during this time.
2. Once I have had both doses of the vaccine am I fully immune?
No, not in all cases.
After receiving two doses of the vaccine some individuals may generate total immunity. However, in some cases individuals may not generate full immunity and may still become infected with COIVD-19 after being vaccinated. It is however likely they will experience a much milder illness and hopefully will not be admitted to hospital.
As patients can still be infected with COVID-19 it is, based on scientific guidance, important to continue to behave as if it is still possible to catch the virus even though you have been vaccinated.
We do not yet have data on whether people who are vaccinated and subsequently contract COVID-19, transmit the virus in the same way. As more populations around the world are vaccinated the effect on transmission will be studied. Therefore, scientists are extremely interested in what is currently happening in Israel as their immunisation program is occurring very quickly.
3. Should I get the vaccine?
Yes. Everyone over the age of 18 should be vaccinated.
Once vaccinated you will have total or partial immunity. This will either be protective and protect you from catching COVID-19 or make a COVID-19 infection mild, so you do not need hospitalisation.
4. Why did the British Medical Association write an open letter to the government asking them to reconsider their decision to administer the vaccine doses further apart than studied in the clinical trials?
Trials have specific parameters. We can only be certain of the effectiveness of a vaccine when following exactly what happened in the trial.
We know the body mounts a response to the vaccine over 2-3 weeks. At around the time we think the body is mounting its maximum response, a second dose is given to make the body generate an even greater response which is likely to last for a longer period of time.
For the Astra Zeneca/ Oxford vaccine trail several ways of administering the vaccine were tested. The subset with the highest protection had the vaccine spaced out, in other words, not administered within the same month.
The Pfizer vaccine trial only has data when given within 3-4 weeks of each other. Doctors and scientists try to give medications based on evidence.
While it may be effective to give the Pfizer vaccine after 3 months following the initial dose, this has not been proven or even examined in the clinical trial.
We currently do not know the definitive answer but the doctors in the UK have written jointly to the government to ask them to shorten the gap between vaccines as they are concerned it may reduce the effectiveness of the vaccination program for both the vaccines above which have been licenced in the UK.
The UK is currently not following the same immunisation pattern as is advised by the World Health Organisation. Therefore, this point is being debated by the experts and why the doctors have written to the government asking them to reconsider their decision to separate the vaccines by three months. The doctors want the vaccines to be given closer together.
5. I have had COVID-19, should I still have the vaccine?
Yes.
After having COVID-19 you will have natural immunity which is usually a strong immunity.
The current advice is to wait 3 months before having the vaccine after an infection so any side effects of the vaccine will not be mistaken for the infection.
For those who have had COVID-19, the vaccine should boost your immune system further and decrease the chance of a second infection.
6. How is the new variant different?
Viruses continually mutate and that is normal. Most of these mutations are irrelevant but some improve the effectiveness of the virus to spread, other mutations may help the virus evade the immune response for example. As these mutations are helpful for the virus, it will naturally become the dominant form of the virus.
The UK is sequencing around 10% of all positive cases. This is where the scientists look at the DNA of the virus. They are looking for changes in the base pairs, deletions or additions to of part of the DNA helix. They check every single position on the virus’s DNA. This is an enormous effort thanks to excellent research scientists who work in the UK.
The new variant is called B.1.1.7 and has 17 mutations, 2 of which appear to be significant. The first significant variation effects the surface protein of the virus and makes it easier for the virus to enter the cells. The second mutation makes it harder for the immune system to “find it” and mount an immune response enabling it to do more damage before it is found by the body and killed.
This variant spread very quickly. On 6th November it accounted for 30% of cases and by 9th December it accounted for 60% of cases in the south east of England. There was such a rapid acceleration in the number of people becoming infected, and such a fast increase in the percentage which were due to this variant it triggered the latest lockdown.
We were aware of this because of the amazing effort going into the sequencing such a high percentage of positive cases in the UK. It is very impressive.
The most significant mutations that appear to be causing concern around the world, are those involving the surface spike proteins as these are the mutations which enable the virus to spread more easily from person to person.
7. What is the difference between IgG and T cell immunity?
In basic terms IgG are the ‘troops’ which go out around the body finding and killing the virus. The T cells are the ‘general’ who remain in HQ in the lymphatic system directing the immune response.
After a COVID-19 infection, once the threat has been neutralised and the COVID-19 infection has been killed, the IgG stop circulating. It is then not possible to find IgG antibodies on the blood test. In practice most IgG immunity has gone within 6 months. A few patients remain positive longer for IgG.
However, we do not know if the T Cells are still alive and well in ‘HQ’. If so, then if a person were to be in contact with COVID-19 again, an immediate immune response is mounted in the form of IgG and that protects the person from further infection. The individual would not even know this had happened.
The immune system is incredibly complex. It is as if you have an air force, a navy, the army, and the SAS protecting you from illness. Antibodies are easy to test for and so are discussed a lot in the media. However, you can still be immune and have a negative IgG antibody test.
This is the immune memory in the T cells.
8. How long does the immune memory last?
We do not know. It is currently unclear how long an infection or a vaccine will give immunity for.
9. How long will this wave last?
Around the 10th January was the peak for cases in the community. Infected people who are going to become unwell usually do so between days 10-14 after becoming infected.
The peak in the hospitals was last week and it will be the peak in ITU in the coming week around the end of January. So, sadly death rates will remain high for some time to come.
The current prediction is that rates will now continue to drop in the community and remain high in the hospital through February. Figures will start to improve overall in March.
As we have better ways of treating people in hospital, patients are not dying at the same rate as in the first wave. However, they are spending longer time in hospital. Therefore, the hospitals will remain busy for some time to come.
10. How long will this pandemic last?
Through history most have lasted for 2-3 years. The second and third waves being worse than the first as we are currently seeing. This may be shortened by the vaccination program. We have yet to see.
11. I have had a positive rapid test. Do I need to do a formal PCR test?
Yes. It is important that you then have a formal PCR test. This is because COVID-19 is a notifiable disease. There has always been a list of notifiable diseases where a central health agency needs to be alerted for contact tracing purposes. Diphtheria for example is on that list.
Once the lab has a positive PCR test there is a whole mechanism which then starts behind the scenes to contact trace and to keep data on the infection centralised.
12. Can I have a positive COVID-19 test because I have been vaccinated?
No. None of the COVID-19 tests that are available would provide a positive test because of the vaccine.
13. If my children have had a positive COVID-19 test, do they still have to have a rapid test, also known as a lateral flow test, to go to school (when opened)?
This is where the sample is taken in the same way but rather than the liquid being sent to the Laboratory for PCR testing the liquid sample is placed on a small absorbent pad. The liquid is drawn along by capillary action. There is a strip in the pad which is coated with antibodies which will bind to proteins in the virus. If the virus is present the strip changes colour and shows up as a positive test.
The answer is yes. Although there are some clarifications to this.
Key workers who have been able to send their children to school still have to have their children tested and this has helped.
However, after a positive test, a lateral flow test can remain positive for up to 90 days so Healthcare workers themselves are currently advised not to have further lateral flow tests within 90 days of an infection even though they are no longer infective the lateral flow tests may be positive.
While people have been infected twice with COVID-19, this is unlikely within this time period as the person should have an immune memory protecting them.
If you or your children have been infected close to when schools re-open, you should discuss with your school.
Welcome to Sloane Square Medical’s first blog. I hope you have enjoyed reading this and have found it helpful.
My best wishes to everyone. I know how hard it has been over the last year. Hopefully, we will start coming through the worst of it in the next few months.
There is so much to look forward to and even though it is still cold the days are already starting to get longer.
My very best wishes,
Dr Victoria Owen