A vaccine developed in China appears to be safe and may protect people from the new coronavirus, researchers reported on Friday.
The early-stage trial, published in the Lancet, was conducted by researchers at several laboratories and included 108 participants aged 18 to 60. Those who received a single dose of the vaccine produced certain immune cells, called T cells, within two weeks. Antibodies needed for immunity peaked at 28 days after the inoculation.
“This is promising data, but it’s early data,” said Dr. Dan Barouch, director of vaccine research at Beth Israel Deaconess Medical Center in Boston, who was not involved in the work. “Over all, I would say this is good news.”
The trial is the first step in testing the vaccine and was intended mainly to verify its safety. Proof of its effectiveness will require trials in thousands, perhaps hundreds of thousands, more people.
A vaccine for the new coronavirus is considered to be the best long-term solution for allowing countries to reopen their economies and return to normalcy. Multiple teams worldwide are racing to test various candidates.
Different Approaches to a Coronavirus Vaccine
Scientists are using many techniques to develop coronavirus vaccines.
Results of just one other human vaccine trial have been published in a scientific journal. That vaccine has now entered mid-stage human trials, the manufacturer, Sinovac Biotech Ltd., said on Friday.
The vaccine reported today was made with a virus, called Ad5, modified to carry genetic instructions into a human cell. The cell begins making a coronavirus protein; the immune system learns to recognize the protein and attack it, in theory preventing the coronavirus from ever gaining a foothold.
But Ad5 is a cold virus that many people probably have already been exposed to. About half of the participants in the trial had powerful antibodies to Ad5 before they got the vaccine.
In these people, “their immune systems will essentially rear up and blunt the effect of the vaccine,” said Dr. Kirsten Lyke, a vaccinologist at the University of Maryland who is leading another coronavirus vaccine trial.
The researchers in China did find that people who had Ad5 antibodies were less likely to develop a strong immune response to the vaccine.
“That may limit the use of this vaccine,” said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine. “If you’re comparing vaccines, the adenovirus ones so far seem to be on the lower end of the spectrum.”
Other teams have turned to adenoviruses to develop coronavirus vaccines, but they are using less common strains, or even animal strains, to circumvent this problem. Dr. Barouch, who is working on an Ad26 vaccine, said his team has data from Africa and Southeast Asia showing that people generally do not have high levels of antibodies to that strain.
Only a subset of people in the new trial produced neutralizing antibodies to the coronavirus, the kinds of molecules needed for immunity. Other vaccine candidates have reported better results in the levels of neutralizing antibodies.
People between 45 and 60 years of age also produced weaker immune responses following vaccination than younger participants. Dr. Lyke said the responses may turn out to be even weaker among people older than 60.
“That’s a very important target population that they would have to examine,” she said. Dr. Lyke suggested that this vaccine might be best suited to younger populations and children.
Frequently Asked Questions and Advice
Updated May 20, 2020
What are the symptoms of coronavirus?
Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days.
How many people have lost their jobs due to coronavirus in the U.S.?
Over 38 million people have filed for unemployment since March. One in five who were working in February reported losing a job or being furloughed in March or the beginning of April, data from a Federal Reserve survey released on May 14 showed, and that pain was highly concentrated among low earners. Fully 39 percent of former workers living in a household earning $40,000 or less lost work, compared with 13 percent in those making more than $100,000, a Fed official said.
How can I protect myself while flying?
If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.)
Is ‘Covid toe’ a symptom of the disease?
There is an uptick in people reporting symptoms of chilblains, which are painful red or purple lesions that typically appear in the winter on fingers or toes. The lesions are emerging as yet another symptom of infection with the new coronavirus. Chilblains are caused by inflammation in small blood vessels in reaction to cold or damp conditions, but they are usually common in the coldest winter months. Federal health officials do not include toe lesions in the list of coronavirus symptoms, but some dermatologists are pushing for a change, saying so-called Covid toe should be sufficient grounds for testing.
Can I go to the park?
Yes, but make sure you keep six feet of distance between you and people who don’t live in your home. Even if you just hang out in a park, rather than go for a jog or a walk, getting some fresh air, and hopefully sunshine, is a good idea.
How do I take my temperature?
Taking one’s temperature to look for signs of fever is not as easy as it sounds, as “normal” temperature numbers can vary, but generally, keep an eye out for a temperature of 100.5 degrees Fahrenheit or higher. If you don’t have a thermometer (they can be pricey these days), there are other ways to figure out if you have a fever, or are at risk of Covid-19 complications.
Should I wear a mask?
The C.D.C. has recommended that all Americans wear cloth masks if they go out in public. This is a shift in federal guidance reflecting new concerns that the coronavirus is being spread by infected people who have no symptoms. Until now, the C.D.C., like the W.H.O., has advised that ordinary people don’t need to wear masks unless they are sick and coughing. Part of the reason was to preserve medical-grade masks for health care workers who desperately need them at a time when they are in continuously short supply. Masks don’t replace hand washing and social distancing.
What should I do if I feel sick?
If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.
How do I get tested?
If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.
How can I help?
Charity Navigator, which evaluates charities using a numbers-based system, has a running list of nonprofits working in communities affected by the outbreak. You can give blood through the American Red Cross, and World Central Kitchen has stepped in to distribute meals in major cities.
The results are based on data from a short period, and it is unclear how long the vaccine’s protection might last.
The researchers tested three doses and said the highest dose seemed to be the most effective. This dose response is encouraging, experts said. But people who got the highest dose also experienced the most side effects.
About 80 percent of the participants reported at least one side effect, all expected with a viral vaccine, experts said. Apart from pain at the injection site, close to half of the participants reported fever, fatigue and headaches, and about one in five had muscle pain.
Experts praised the researchers for publishing all of their data for others to review, and said the results were promising over all.
“What we hope is that there will be not one vaccine but several vaccines that will be approved,” Dr. Barouch said. “The world needs multiple vaccines.”