The coronavirus pandemic has had a major impact on blood donations. On the subject, we interviewed Daniele Prati, director of the Department of Transfusion Medicine and Haematology at the Policlinico di Milan, who also spoke to us about the role of blood tests in the so-called “phase 2”.
They call it the happy island. The Marangoni pavilion of the Policlinico di Milan. And not because there is anything special about it, but because it is the only one that has not been designated for the care of patients with Covid-19. It is the facility where, in normal times, around 120 people a day come to donate blood. At the beginning of the epidemic, that figure fell to no more than 35. But it is a trend that, fortunately, lasted very briefly, thanks in part to the appeals and reassurances of the Ministry of Health and Civil Protection, which explained that there is no scientific evidence of the virus being transmitted through transfusion. At that point the flow of donors actually became anomalous, reaching peaks of over two hundred people a day.
"The response from our donors has been truly exceptional. Here at the Policlinico people are very motivated and they respond enormously." The words are those of Daniele Prati, director of the Department of Transfusion Medicine and Haematology at the Policlinico di Milan, who explains: "Disasters — and this is one in a sense, given its exceptional nature — bring blood donors in. It happened after 11 September and after earthquakes too. An epidemic, though, is a little more insidious."
Every day in Italy, around 1,800 people receive a blood transfusion. That is why, as Gianpietro Briola, president of Avis (Associazione volontari italiani di sangue), explained in an interview on La7, donation "remains a fundamental moment for the maintenance of the national and regional health service." But what has been the impact of coronavirus on blood donations? How has the initial triage stage changed? What is meant by plasma therapy? These are just some of the questions we put to Dr Prati.
Dr Prati, have you noticed any changes in blood donations since the Covid-19 epidemic broke out?
The epidemic broke out on Friday 21 February. The following week we were all frightened: whereas in normal times the Policlinico receives 120 donors or more, on Monday 24 only 35 came. Tuesday was more or less the same. Fortunately we managed to reassure donors that they could come and donate blood without any worry. So in the weeks that followed, during which the various lockdown measures were put in place, also thanks to the appeals from the Ministry of Health itself and from Civil Protection, the flow of donors reversed: a great many people came. We had a week, around 8 March, when the number of donors was actually anomalous. More than two hundred people came.
We had clearly had to implement all those measures to contain the risk of transmission, even though we were dealing with apparently healthy people, within the facility. As regards distancing, we tried to limit the number of people inside the pavilion, moving the waiting phases outside or into other rooms. Then the situation settled down somewhat. This collection peak led us to set aside a reserve of blood units, which also proved useful in the weeks that followed, because we are currently collecting around 25 per cent less blood than last year.
It is also true that this 25 per cent is counterbalanced by the same 25–28 per cent reduction in demand for blood. Since the hospital has entirely turned itself over to caring for Covid-19 patients, a large part of the other activities — such as elective surgery, that is surgical procedures that are not performed as emergencies but can be deferred — has indeed been deferred. Everything that was not urgent has been postponed. This thinning out of certain activities, which were previously guaranteed and carried out on a regular basis, has in parallel led to a reduction in demand.
Among those who come to donate, are there more new donors or regular donors?
There have also been many new donors. It is a trend described in the literature: disasters — and this is one in a sense, given its exceptional nature — bring blood donors in. It happened after 11 September and after earthquakes too. An epidemic, though, is a little more insidious, because for one thing it lasts over time and then because it can take away staff and donors, who may have been in contact with positive individuals and have to go into quarantine. This reduction risks putting the system under strain.
The other thing we need to watch very carefully is the resumption of activities: there could be a rebound there that we might struggle to counterbalance. We are fortunate in that we have the ability to freeze blood. The Policlinico is the reference centre for the whole of Lombardy as regards rare blood; for this reason, instead of keeping bags in a refrigerator for 42 days until they expire, we freeze them. This is something that 95 per cent of other transfusion centres are unable to do. Whatever we collect in excess, we either use ourselves or pass on to other centres that need it. There is a fairly effective network system.
Yet the impression is that something catastrophic always has to happen to somehow awaken the awareness of donors.
To some extent, yes — we here are on a happy island. We are practically self-sufficient; we do not need support from external facilities, except in exceptional circumstances. This is not the case for the rest of Milan, which depends on blood coming from Lecco, from Garbagnate, from the province. The blood we collect at the Policlinico serves half of Milan; we give it to the European Institute of Oncology, to the Gaetano Pini, to the Monzino. We support all these external organisations, as well as the Policlinico itself.
Donating blood within a facility that is an Irccs — that is, an Istituto di ricovero e cura a carattere scientifico (Scientific Institute for Research, Hospitalisation and Healthcare) — also supports research. We carry out a great many research projects aimed at understanding how a healthy individual functions. It is difficult to understand how disease works, but to do so we must have a deep knowledge of health. It is almost dichotomous — it works like a mirror. And this is all the more important when dealing with advances linked to genetics or personalised medicine.
Someone goes to donate and is told they save three lives, through plasma, platelets and red blood cells — but they also help themselves to live better, because they receive a periodic medical and clinical assessment that helps them keep themselves in check. Then, if the blood they donate is incorporated into research programmes, the whole thing yields a considerable return both for the individual and for others.
Has the way in which donors' blood is analysed changed during this phase?
No, it has not changed, except in the context of clinical studies. There are some studies, in which we too are involved, where additional tests are carried out on donors who could represent an excellent sentinel population for understanding where we have got to with the infection. If what is being said is true, beyond confirmed cases we should perhaps have even more cases of people who may have encountered the virus and developed antibodies. That does not always mean they are then protected: having antibodies means having come into contact with the virus. Whether those antibodies are protective, no one is yet able to say. However, we could at least find out how far the virus has travelled and perhaps, by examining samples preserved in the past, also manage to understand when it was introduced. That is another piece of information that is missing. It is said that the virus was probably already circulating more widely than it appeared at the end of February. Studies on donors could help us understand that.
We have not changed the way we analyse blood, but we have intensified the entire initial triage process, during which a series of questions are asked to establish whether a person has had contact with at-risk individuals or is at risk of having contracted the infection, their temperature is taken, and donors are advised, after donating, to provide information should they develop any particular symptoms. In that case we would quarantine the blood unit. There is also a great deal of interest in donors who have recovered from the virus, though these are experimental protocols.
Are you referring to plasma therapy — the technique already used for other respiratory infections such as Sars and Mers, which involves treating Covid-19 patients with plasma from recovered patients?
Exactly. It was used for Sars and Mers, but the data on its effectiveness are very scarce. In the sense that the studies were probably not conducted in an adequate or sufficiently exhaustive manner. A couple of reports of efficacy have come out of China, but efficacy in individual cases. What are needed are randomised studies: I take a group of people I treat with plasma and another group equivalent to the first, selected at random, whom I do not treat with plasma. Then I check whether the mortality rate differs. That has not been done at this point in time.
Nevertheless, there is interest in selecting individuals who have been exposed to the infection and have developed antibodies. Thanks to these individuals, for instance, specific immunoglobulins could be produced — perhaps not so much for use in treating the sick but in prophylaxis, that is, trying to protect people who might become infected and are in contact with the infection. Think of elderly people in care homes. Should this infection return in a few months' time, it could prove an effective technique.
Do you think it is a plausible hypothesis that the virus may weaken during the summer months and could then reappear later on?
I am already someone who tends to have few certainties; in this case I have even fewer, because this is a virus no one has ever seen before and it frankly leaves me astonished. Fascinated by it, too, as I observe it. We are slowing the spread of an epidemic, which means spreading it out over time. We will probably have to get used to it, because it could return in the future if we are so good at making it disappear right now. That the heat might help is possible, but there is still no scientific evidence for it.
Do you think rapid blood tests that identify the presence of antibodies to the virus could be an effective tool for phase 2?
I think so. However, we must not assume prematurely that these rapid blood tests — for instance those that look for antibodies — truly tell us that if someone has been exposed they cannot fall ill again. They are certainly useful, because they are an additional tool, and they should therefore be evaluated. It will certainly be useful to test blood donors, as it will give us a clear picture of what has happened in these months. But we will still have to learn how to use them.
There are already fifty tests filed with the Ministry of Health for commercialisation in Italy; of these, few are produced in Italy, while others are produced abroad. It will be necessary to establish which is the best. The first task will be to understand the sensitivity and specificity of these tests. Improving both the availability and the quality of swabs will also be crucial.
In what way?
More will need to be carried out, especially should we face new waves of the epidemic, in order to be more precise in isolating a resurgence of the epidemic. On quality, we will need to improve: so far we have used the first tests that became available; it may well be that over time the quality of these tests improves and yields fewer false negatives, because there have been a few.
Testing is fundamental; blanket testing is difficult to carry out and can sometimes even worsen the situation because — history teaches us — when tests or therapies are administered on a blanket basis, people are brought together and the risk is that of facilitating the transmission of the virus among individuals. They will need to be conducted with care and patience. There is a fine study from the New England Journal of Medicine on the Icelandic population, in which a large number of tests were carried out. But let us be clear: Iceland's population is far smaller than Milan's.
If you feel up to venturing a prediction for the future: how do you think this situation will develop in terms of evolution and timescales?
We will have to change our habits for a while. If, as they say, protective antibodies exist, it is probably possible to design a vaccine that works. With current timelines, a vaccine could be available by the end of the year. So I might say: let's give it a year and a half from now. But there is still much to understand about the natural history of the disease: we have not fully understood what happens in a patient when they fall ill, or why some come through it completely unscathed while others die.
What makes the difference? The amount of virus a person inhales? That could be the case, but no one has ever proved it. The fact that the virus finds a way to travel systemically to the lungs or other organs? That could be, but this too has never been demonstrated. Could it be that some people have a genetic make-up that favours a milder course while others have a genetic make-up that amplifies an abnormal response, thereby leading to these consequences? In short, there are still many questions we have not answered. And as for how immunity develops, we should be careful about asserting that those who have already been exposed can return to the community. Will that be true? No one has demonstrated it so far.
Herd immunity still seems a long way off.
For herd immunity to exist, the proportion of the population exposed to the virus needs to be in the order of approximately 60 per cent. We are probably still well short of that. Even assuming that 20 or 30 per cent of healthy people already have the antibodies, we are still far from it. The social dimension is difficult. We talk to one another without seeing each other fully, our faces covered by masks. If nothing else, it will be a great social experiment.