A Study of TAK-919 in Healthy Japanese Adults (COVID-19)

TAK-919 is a vaccine in development to protect people against Covid-19. The main aims of the study are to learn if TAK-919 can protect people from Covid-19 and to check for side effects from TAK-919.

At the first visit, the study doctor will check if each person can take part. Those who can take part will be chosen for 1 of 2 treatments by chance. Participants will either receive an injection of TAK-919 or a placebo in their arm. In this study, a placebo will look like the TAK-919 vaccine but will not have any medicine in it. 3 times as many participants will receive TAK-919 than placebo. Participants will receive 2 injections of TAK-919 or placebo, 28 days apart.

Participants will be asked to record their temperature and any medical problems in an electronic diary for up to 7 days after each injection.

During the study, participants will visit the clinic for regular check-ups, blood tests, and sometimes for nose swab samples. When all participants have visited their clinic 28 days after their 2nd injection, the study sponsor (Takeda) will check how many participants have made enough antibodies to protect them against Covid-19.

The participants will stay in the study for up to 12 months after they have had their 2nd injection. During this time, the study doctors will continue to check how many participants have made enough antibodies to protect them against Covid-19. Also, they will check if participants have any more side effects from TAK-919 or the placebo.

The drug being tested in this study is called TAK-919. TAK-919 is being tested to prevent infectious disease caused by Severe Acute Respiratory Syndrome coronavirus-2 (SARS-CoV-2). This study will look at the safety and immunogenicity of 2 doses of TAK-919 by intramuscular (IM) injection in healthy Japanese male and female adults, given 28 days apart.

The study will enroll approximately 200 healthy volunteers. Participants will be randomly assigned (by chance, like flipping a coin) to one of the two treatment groups-which will remain undisclosed to the participant and study doctor during the study (unless there is an urgent medical need):

* TAK-919 0.5 mL
* Placebo- this is an injection that looks like the study drug but has no active ingredient

All participants will be asked to take intramuscular injection in the upper arm twice throughout the study.

This multi-center trial will be conducted in Japan. The overall time to participate in this study is 12 months from the second vaccination. Participants will make multiple visits to the clinic and will be contacted by telephone or a final visit after the last vaccination for a follow-up assessment.

Eligibility Criteria:
Inclusion Criteria:

1. Healthy Japanese male and female participants.
2. Participants who understand and are willing to comply with trial procedures and are available for the duration of follow up.

Exclusion Criteria:

1. Participants who received any other SARS-CoV-2 or other experimental novel coronavirus vaccine prior to the trial.
2. Participants who have close contact of anyone known to have COVID-19 within 30 days prior to vaccine administration.
3. Participants who were tested positive for SARS-CoV-2 prior to the trial or on the test before the vaccination.
4. Participants who are on current treatment with other investigational agents for prophylaxis of COVID 19.
5. Participants who traveled outside of Japan in the 30 days prior to the trial participation.
6. Participants with a clinically significant active infection (as assessed by the Investigator) or oral temperature \>= 38 degree Celsius within 3 days of the vaccination.
7. Participants with a known hypersensitivity or allergy to any of the IMP components.
8. Participants with any illness or history of any illness that, in the opinion of the Investigator, might interfere with the results of the trial or pose additional risk to the participants due to participation in the trial.
9. Participants with known or suspected impairment/alteration of immune function, including history of any autoimmune disease or neuro-inflammatory disease.
10. Abnormalities of splenic or thymic function.
11. Participants with a known bleeding diathesis, or any condition that may be associated with a prolonged bleeding time.
12. Participants with any serious chronic or progressive disease (eg, neoplasm, insulin dependent diabetes, cardiac, renal, or hepatic disease).
13. Participants with BMI \>= 30 kg/m\^2 (BMI=weight in kg/height in meters\^2).
14. Participants participating in any clinical trial with another investigational product within 30 days prior to the vaccination or intend to participate in another clinical trial at any time during the conduct of this trial.
15. Participants who received or plan to receive any other vaccines within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to trial dose administration.
16. Participants with acute or chronic clinically significant disease including pulmonary, cardiovascular, hepatic, or renal abnormality evaluated by physical examination.
17. Participants involved in the trial conduct or their first-degree relatives.
18. Participants who are with or have history of hepatitis B and hepatitis C infection, or with known human immunodeficiency virus (HIV) infection or HIV-related disease..
19. Female participants who are pregnant or breastfeeding.