using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<string> vaccines = new List<string> { " ", "", null, "RealVacc", "RealVacc2" };

        var populatedVaccines = vaccines.Where(v => !string.IsNullOrWhiteSpace(v)).ToArray<string>();

        populatedVaccines.Dump();

    }

}