The peak is approaching, new mutations are coming, the value of vaccines is in question, but there is no question about the usefulness and use of rapid tests, tips on the saliva test or nasal test.
In November 2021, at the height of the fourth wave of the coronavirus epidemic, the number of new infections, hospitalisations and deaths is increasing daily.
When could the peak of the fourth wave be?
According to mathematicians and experts, this fourth wave could peak in early December. However, different epidemiological data show that the peak is reached at different times, virologist Miklós Rusvai warns in a response to B&L Online News and Articles. First, the number of newly infected will peak, followed by the number of people in hospital, then those on ventilators, and finally, about three weeks after the peak in infections, the number of deaths will be at their highest level. This could mean that all epidemiological indicators are likely to peak between the beginning of December and Christmas, and then gradually start to decline from there.
Delta, delta plus, omicron and others: how dangerous are the new mutants?
In Hungary, the so-called delta variant of the coronavirus will be circulating by the end of 2021, but a subspecies, delta plus, has already been detected and is responsible for more than a tenth of current infections. The new omicron mutation from South Africa has not yet appeared in Hungary, but it has in the Czech Republic and Germany. There are already more than 16,000 mutants of the SARS-CoV-2 virus, including at least 12 variants of the delta virus that have been positively detected, four of which are found in Europe.
“The coronavirus is so susceptible to mutation that a virus that is unique to each patient could be detected in almost every patient,” says Miklós Rusvai. “The only reason we are not finding more mutants is that genetic testing of these viruses is not always done, but most of the mutations are not even relevant to detection and cure”. For mankind, the most important part of the viral genome, which consists of about 29 700 units (nucleotides), is the part that codes for the spike protein, which is only one eighth of the total, about 3.5 thousand units. What may be relevant is if there is a change in these, but only if the mutation alters the virus’ ability to spread or cause disease, or its resistance to vaccines. “We are only looking at these three characteristics of the variants of the coronavirus, they are the ones that are important to us, all the other variations are less interesting. So the number of mutants of interest to mankind is relatively limited,” says the virologist.
However, even then, the question remains whether new mutants may emerge in the future against which existing vaccines may not be effective, and new vaccines will have to be developed, which could take many months, or even years. Miklós Rusvai answers with a firm no. “There can be no fundamental change in the spike protein that existing vaccines cannot protect against. The coronavirus binds to the surface of our cells with the help of the spike protein. If this were to change so much that the vaccines would not protect against the coronavirus, the virus would not be able to bind to our cells. This means that as long as we are infected by the coronavirus, we will be protected by the vaccines currently on the market. At most, their efficiency may be reduced by a few percent.”
Can we use, should we use, a quick test at home?
As the epidemic spreads, the need for tests that can be used at home is growing. Today, manufacturers can bring increasingly sensitive rapid diagnostic tools to market. The ECDC, the European Centre for Disease Prevention and Control, has so far advocated the use of nasopharyngeal and nasal cavity tests, with few comparative studies of any scientific value on saliva-based tests. However, two of the newer saliva tests are also more sensitive than most of the nasal cavity tests. According to a study by the German Paul Ehrlich Institute, there are hardly any other saliva tests that meet the Institute’s standards, so it is worth being very careful when buying saliva tests. But easy-to-use, painless saliva tests may still have a future. Miklós Rusvai agrees, although he notes that the sensitivity of antigen tests will never match that of nasopharyngeal PCR tests. But they do not necessarily need to be compared, because they serve different purposes. Rusvai adds that whether it’s a nasal swab, saliva-based test or a throat swab, it is primarily used to see if a person is infectious, because these rapid tests can only detect large amounts of virus. As newer and newer mutations become more infectious, with higher and higher concentrations, they are easier to detect in tests. The virologist cites as an example that the infectivity of the current delta plus variant has increased two and a half times compared to the original Vuhan virus two years ago, meaning that it is produced in greater quantities in our cells.
According to Attila Karvalics, CEO of A-Lab Pharma, a leading player in the private (non government-ordered) testing market for the general public and institutions, the accuracy of tests has steadily improved along with the increase in virus concentration. A year and a half ago, an antigen test with a sensitivity of 75-80% was at the top of the league, but today they are among the leaders,” says Karvalic. He says that we need to look very carefully at what companies and individuals are buying, because a few percentage points difference in test sensitivity can multiply the number of false results. In other words, he says, you should only look for the best in tests, and better is not necessarily more expensive, but more expensive is not necessarily better. “There are saliva tests that have performed better in independent trials than the renowned nasal tests, but the vast majority of saliva tests today do not yet reach the level of marketability according to our standards,” says the CEO, who from the beginning has selected the tests represented by the company exclusively on the basis of his own and partner trials, trials or the results of independent studies, aiming to provide customers with the highest analytical values currently available.
It’s worth testing in the morning
In the context of home testing, Rusvai points out that both the nasal cavity and saliva have higher concentrations of the virus at rest, i.e. in the morning. During the day, when we are awake, eating, drinking and blowing our nose, secretions are constantly being discharged from the nasal cavity and the oral cavity. At night, when we are asleep, they are much less likely to be cleared quickly, meaning they accumulate the virus. So, if there is a build-up of viral mucus in the oral cavity or nasal cavity, it can be detected better when we wake up because it is present in greater quantities.
Overall, Miklós Rusvai considers the use of home rapid tests to be good, and compares them with home pregnancy tests. No gynaecologist will accept that, but will carry out tests with much more professional parameters, but they can still provide the family with information. Likewise, for the information of private individuals, it considers home-use coronavirus tests with immediate results useful, which can be used to carry out further tests and speed up the process of containing the virus, identifying contacts, testing and taking action.