COVID-19: VACCINES - ARE WE MISSING THE OBVIOUS?

According to the London School of Hygiene and Tropical Medicine, there are now 239 vaccines against COVID-19 worth tracking, of four main types.

The UK Government has committed to sourcing six of these across all four main types, should one or more of them be successful.

But is there one type missing?


EXISTING VACCINE PROGRAMMES

The view of most experts is that a vaccine is likely to become widely available by mid-2021.  Some nine months from now, and certainly not this side of Christmas 2020.  That timescale seems realistic, but still no guaranteed.

These were the first two vaccine trials to report that an immune response had been achieved back in July:

• The 'Oxford vaccine' is based on a common cold virus found in chimps.  
• One of the 'Chinese vaccines' uses a human common cold virus modified to mimic SARS-COV-2, the virus that causes COVID-19.  

Note the common theme - 'common cold'.  The relevance of this is that 15-20% of common cold infections in humans are thought to be caused by other corona viruses.  Only mild to medium symptoms.

Not any type of common cold.  Only those caused by four types of corona viruses, types 229E, NL63, OC43, and HKU1.  Other viruses are irrelevant.


CROSS-IMMUNITY

We hear about antibody tests and the importance of antibodies in the immune response.  These are produced by B cells.  But research has shown that T cells that can respond to SARS-COV-2 (SARS2) are created as a response to one or more of the common cold corona viruses.  The T cell response is known to last a long time, probably longer than antibodies.

Recent research has "... now proven that, in some people, pre-existing T cell memory against common cold coronaviruses can cross-recognize SARS-CoV-2".

This is consistent with other reports of cross-immunity from common cold corona viruses.  This may explain why Sweden's rate of new infections is much lower than might be expected for the SARS2 virus acting alone.

The advantage with a vaccine based on cross-immunity is that it could not only provide immunity against SARS2, but also against the other deadly coronaviruses SARS, and MERS, should they re-appear.  Or against new future SARS3 or SARS4 if they were to be as infectious as SARS2 and as deadly as MERS, for which one in three infected people die.

There is one concern with cross-immunity.  Some diseases such as Dengue fever cause a more severe infection when someone originally infected by strain A is subsequently infected by B C or D.  An effect known as "Antibody-Dependent Enhancement" (ADE).  As yet the cross-immunity for SARS 2 appears to be only a benefit, without such a problem. Fingers crossed.



A DIFFERENT TYPE OF VACCINE

Like this perhaps?

The obvious response to cross-immunity is to develop a vaccine that is based directly on one or more of the four common cold coronaviruses.  Or indeed just breath in the appropriate viral cocktail.

So is that the way forward?  Not a jab in the arm, but snorting one or more types of live common cold coronaviruses?

I'd happily have the snuffles for two or three days if it gave me immunity against COVID-19.  Indeed I would be first in the queue.  Wouldn't you?




THE PRACTICALITIES

A successful vaccine has to do six things, however administered, whether that is by a jab or breathing it in:

1. Provide immunity, for a significant period
2. Be 'safe', with any side-effects acceptable compared to the target disease
3. Easily prepared
4. Capable of distribution, e.g. whether needs refrigeration
5. Easy to administer by people with basic training
6. A low enough cost for mass usage

The big 'if' is obviously whether it would work.  Research into the effectiveness of the four different coronaviruses is required.  But indications so far suggest this is a distinct possibility.


On safety, provided the only symptoms are what we know of the common colds caused by corona viruuses (ignoring other types of viruses), that would be fine.  Clearly safety tests would be necessary.

For preparation, a batch or continuous production process for a line of specific coronaviruses  would presumably be no more difficult than other processes in the pharmaceutical industry.  Distribution likewise.


If all that was needed was to breath in the viral cocktail, without the need for injections, it would be easy enough to do at home or with minimal supervision.

Cost?  Potentially far less to prepare a viral cocktail to be inhaled than the other vaccines in development.


COMMON COLD PARTIES

It may be possible to distribute the viral cocktail of common cold coronaviruses even more easily and cheaply if one person was infected and they then held a  'common cold party'.

Rather like parents would get their kids to catch chicken pox in a 'pox party', to avoid shingles in later life which is far worse as an adult.

Remembering that nobody with an immune weakness should catch any form of infection.


REALISTIC?

A quick internet search found nothing about any development of vaccines based on just catching a coronavirus common cold.

Is this unrealistic?  Or is this actually the solution to getting an easy, cheap vaccine quickly to people that will allow life to get back to 'normal'?

Just an idea as yet.  But not the first time you would have heard something important here first.

Fingers crossed.  Watch this space!