Error Code: 1292. Truncated incorrect INTEGER value: '' with Temp table

Question

I'm receiving this error: Error Code: 1292. Truncated incorrect INTEGER value: ''

I'm trying to create a temp table:

Create Table PercentPopulationVaccinated
(Continent varchar(255),
Location varchar(255),
Date Datetime,
Population Numeric, 
New_vaccinations numeric,
RunningTotalofVaccinations numeric
);

insert into PercentPopulationVaccinated
select dea.continent, dea.location, str_to_date(dea.date, '%Y-%M-%D'), 
convert(dea.population, signed int), convert(vac.new_vaccinations, signed int), 
       sum(cast(vac.new_vaccinations as signed)) 
           over(partition by dea.location 
                order by dea.location ROWS UNBOUNDED PRECEDING) RunningTotalVaccinations
From CovidDeaths dea
join CovidVaccinations vac
    on dea.location = vac.location
    and dea.date = vac.date
    -- where dea.continent is not null
    order by 2, 3;

It creates the table but when I try to run the Insert into.. code it gives that error.

I think it's the data- these are the values of the two tables:

dea.continent - varchar (100)
dea.location - varchar (100)
dea.date - varchar (100)
dea.polulation - double
vac.new_vaccinations - varchar (100)