COVID-19 vaccine unlikely soon, precaution best defence: WHO official

The coronavirus positive cases in the country crossed the five lakh mark on Saturday and hit the highest single-day spike of 18,552 cases, according to central government data.

We talk to the World Health Organisation's (WHO) South-East Asia Regional Director Dr. Poonam Khetrapal Singh on the challenges caused by COVID-19 and the ongoing vaccine experiments:

What are the major Covid vaccine experiments that go on? Could you please elaborate on that?

As of 17 June, there are 128 candidate vaccines in pre-clinical trial phase. In this phase the candidate vaccines are tested on animals for their efficacy.

Once the candidate vaccines clear the pre-clinical trial phase, they enter clinical trial which has three phases.

Currently there are 13 candidate vaccines in the clinical trial phase, with three of them in the phases 2 and 3. They are the ones being developed by University of Oxford / AstraZene, Moderna/NIAID and CanSino Biological Inc./Beijing Institute of Biotechnology. We expect to see results by the end of this year, although we cannot predict at this stage whether these vaccines will meet the necessary standards.

After clearing the clinical trials, the next steps would be licensing and launch in the market. Even while in use, the vaccines will continue to be assessed.

Approximately how much time will be taken to finalise a vaccine? And what is the protocol?

Usually several years. Even with an accelerated process, development of a vaccine for COVID-19 will take time. WHO is working with partners all over the world to accelerate research and development of a safe and effective vaccine and ensure equitable access for the billions of people who will need it.

Why has WHO advised the world not to use HCQ? What are the possible side effects?

On 17 June 2020, WHO announced that the hydroxychloroquine (HCQ) arm of the Solidarity Trial to find an effective COVID-19 treatment was being stopped. The decision was not taken by the WHO but by the trial’s Executive Group comprising of experts from across the globe.

The trial's Executive Group and principal investigators made the decision based on evidence from the Solidarity Trial, UK's Recovery trial and a Cochrane review of other evidence on hydroxychloroquine.

Data from Solidarity (including the French Discovery trial data) and UKs Recovery trial both showed that hydroxychloroquine does not result in the reduction of mortality of hospitalized COVID-19 patients, when compared with standard of care.

This decision applies only to the conduct of the Solidarity Trial and does not apply to the use or evaluation of hydroxychloroquine in pre or post-exposure prophylaxis in patients exposed to COVID-19.

Remdesivir or Dexamethasone can be good alternatives?

WHO welcomes the initial clinical trial results from the United Kingdom that show dexamethasone, a corticosteroid, can be lifesaving for patients who are critically ill with COVID-19. For patients on ventilators, the treatment was shown to reduce mortality by about one third, and for patients requiring only oxygen, mortality was cut by about one fifth, according to preliminary findings shared with WHO.

The benefit was only seen in patients seriously ill with COVID-19 and was not observed in patients with milder disease.

Dexamethasone is a steroid that has been used since the 1960s to reduce inflammation in a range of conditions, including inflammatory disorders and certain cancers. It has been listed on the WHO Model List of Essential Medicines since 1977 in multiple formulations, and is currently off-patent and affordably available in most countries.

The researchers shared initial insights about the results of the trial with WHO, and we are looking forward to the full data analysis in the coming days. WHO will coordinate a meta-analysis to increase our overall understanding of this intervention. WHO clinical guidance will be updated to reflect how and when the drug should be used in COVID-19.

Remdesivir is also part of the multi-country solidarity trial. The WHO welcomes the recent data from a U.S. government-run clinical trial showing the drug appeared to be effective in reducing recovery time for COVID-19 patients. However, the drug has not been formally approved to treat the virus in US and it was granted for emergency use. Other than the Solidarity Trial, many other trials are testing the drug as an effective option in fighting COVID-19.

It is a new virus, it seems the world takes time even to understand it fully. So far, what are the salient features of the virus? How many strains have found?

Current information suggests that the virus can cause mild, flu-like symptoms as well as more severe disease. The most common symptoms of COVID-19 are fever, dry cough, and tiredness. Other symptoms that are less common and may affect some patients include aches and pains, nasal congestion, headache, conjunctivitis, sore throat, diarrhoea, loss of taste or smell or a rash on skin or discolouration of fingers or toes. These symptoms are usually mild and begin gradually. Some people become infected but only have very mild symptoms.

From data from multiple countries, the majority of cases have a mild or moderate form of disease (40% mild; 40% moderate disease defined as radiology-confirmed pneumonia), about 15% progress to severe disease, and 5% are critical.

This is a new disease and our understanding is changing rapidly. We will continue to analyse information on both current and any new cases, as this is critical to enhancing our understanding of severity.

The incubation period for COVID-19, which is the time between exposure to the virus and symptom onset, is on average 5-6 days, but can be as long as 14 days.

Researchers around the world are working hard on accelerating the development of vaccines and therapeutics for COVID-19. WHO has launched various working groups to accelerate various aspects of vaccine development. A call was made by 130 scientists, funders and manufacturers to help speed the availability of a vaccine against COVID-19.

Together with global health actors and partners, WHO launched the Access To COVID-19 Tools (ACT) Accelerator, a global collaboration to accelerate the development, production and equitable access to new COVID-19 diagnostics, therapeutics and vaccines. A global technology access pool has been launched to encourage voluntarily sharing of COVID-19 health technology related knowledge, intellectual property and data.

Human viruses can evolve, becoming less or more pathogenic. Based on the current evidence, the transmissibility and severity of COVID-19 haven’t changed. We are constantly observing these two factors in our efforts to better understand the virus.

The reproduction number of COVID-19 (which measures the transmissibility) is naturally above 2, which means it has an epidemic potential to take off if we allow it to. And this feature remains true so far across countries. Severity remains also consistent. We know that the virus causes a range of illnesses, with a majority of people having experienced mild symptoms and 20% a more severe disease.

How does this virus turn out to be a killer? What causes fatality even among young people and kids?

The crude clinical case fatality rate currently of about 7% (total deaths divided by total cases). Risk factors for severe disease are older age and co-morbidities.

Current findings show that children seem to be less affected, amounting to 3% of all reported cases globally, and those who are infected and detected through surveillance system, have mild disease and recover.

We have seen to a much lesser extent transmission from children to adults being documented in certain household studies, but we currently don’t see this trend in the epidemiology. At this stage, we need more case reports to understand what role children are playing in the transmission of the disease and this is what we are trying to do through our epidemiology studies, which include infection in children.

Recently, asymptomatic Covid patients' transmission potential was widely discussed. Do they spread disease as much as people with symptoms?

COVID-19 is caused by a new virus and we are still learning about the disease every day. We need more data to better understand transmission. Current evidence suggests that most transmission of COVID-19 is occurring from symptomatic people to others in close contact.

It is still unknown how much transmission is driven by people without symptoms. Comprehensive studies on transmission from asymptomatic individuals are difficult to conduct, but the available evidence from contact tracing reported by Member States suggests that asymptomatically-infected individuals are much less likely to transmit the virus than those who develop symptoms.

In Kerala, disease rate is on the rise. What is the ideal way to face this challenge?

The cornerstone of response to COVID-19 pandemic is to find, isolate, test and care, trace and quarantine contacts, whatever the transmission stage. Aggressively implementing these core public health measures; promoting hand hygiene, cough etiquette and social distancing are every country’s best defence against COVID-19.